Download Tumours. Aetiology, classification, diagnostics and treatment.

Lecture 15.
“Tumours. Aetiology, classification, diagnostics and treatment.”
A tumour is a new formation of cells of independent growth which fulfils no useful
function. The term 'tumour' should be reserved for new growths; its loose application to
inflammatory swellings, such as Pott's puffy 'tumour', or to enlargement of an organ due to
hypertrophy, should be abandoned.
Causation.—Over 300 years ago it was stated that 'any kind of external irritation, whether from
motion, heat, or acrimony, may cause cancer'. Natives of Kashmir are prone to cancer of the
skin of the thighs and lower abdomen. This is due to their habit of keeping warm by squatting
and hugging earthenware pots containing glowing charcoal (the pot being termed a kangri),
with the result that the adjacent skin is irritated by heat and fumes. 'Chimney-sweeps" cancer ,
and 'countryman's lip', and tar workers' cancer are other examples of carcinoma due to chronic
irritation.
Regeneration of tissue, with possibly the awakening of erstwhile dormant embryonic cells, may
encourage malignant changes. Primary carcinoma of the liver is sometimes seen in cases of
cirrhosis, and arises from the liver cells which are endeavouring to regenerate. Similarly,
squamous-celled carcinoma occasionally occurs in a chronic ulcer, also Marjolin's ulcer in a
scar. A fibrosarcoma arising in a scar is not uncommon.
Viruses cause nucleal instability and are therefore implicated in some tumour origins, e.g.
Burkitt's lymphoma, Kapozi's sarcoma. A wart is the commonest example of a virus causing a
tumour.
DEFINITIONS
Metaplasia.—The epithelium from which the tumour grows has already changed its
characteristics, e.g. bladder transitional epithelium to squamous epithelium, gallbladder
columnar to squamous epithelium, bronchial columnar to squamous epithelium, even gastric
columnar epithelial pattern to intestinal epithelial pattern.
Anaplasia.—Tumours produce cells which resemble those from which they arise, but with rapid
growth the resemblance is less obvious (anaplastic change).
Teratomas arise from 'totipotent' cells, containing representative cells from all three embryonic
layers: ectoderm, endoderm, mesoderm. Teratomatous 'dermoids', for example, contain hair,
teeth, muscle, gland tissue. An unusual type is the sacrococcygeal teratoma which can be
considered as foetus infoetu (an 'included' foetus).
Blastomas develop from uni potent cells, and arise from any one of the three embryonic layers
(e.g. neuroblastoma).
Innocent or Malignant.—An innocent or benign tumour is usually encapsulated, and does
not disseminate nor recur after removal. Symptoms and effects, which can be harmful, are due
to its site, position, and pressure. Certain adenomas secrete a hormone which may affect bodily
functions. Innocent tumours are often multiple.
Malignant Tumours.—The characteristics of malignancy are: (a) Invasion of surrounding
tissues, (b) pleomorphism (variable shapes) of cells, (c) rapid growth, (d) the tendency to spread
to other parts of the body by the lymphatics and the blood-stream, (e) general weight loss.
It has been suggested that the division of tumours into these two major groups imposes a
concept which is too rigid. A third group of intermediate tumours exists which includes
carcinoid tumours, 'adenoma' of the bronchus, 'mixed' salivary tumours, basal cell carcinoma,
etc. These intermediate types invade locally, but are much less inclined to lymphatic or
especially vascular dissemination.
BENIGN TUMOURS
Adenoma.—Adenomas arise in secretory glands, and resemble the structure from which they
arise. They are encapsulated, and sometimes they profoundly influence metabolism, as in the
case of the thyroid, parathyroid and pancreas. Occasionally an adenoma contains a large
proportion of fibrous tissue, e.g. the hard fibro-adenoma in the breast, while in other situations,
notably the pancreas and thyroid gland, cystic degeneration is common. Those arising from
secretory glands of mucous membrane are liable to pedunculation, as in the case of rectal
'polypus'.
Papilloma.—A papilloma consists of a central axis of connective tissue, bloodvessels, and
lymphatics; the surface is covered by epithelium, either squamous, transitional, cuboidal or
columnar, according to the site of the tumour. The surface may be merely roughened, or
composed of innumerable delicate villous processes, as in the case of those occurring in the
kidney, bladder and rectum. In these situations papillomas resemble malignant tumours, as
secondary growths arise by implantation, and, sooner or later, the tumour becomes frankly
malignant. Other common sites for papillomas are the skin, the colon, the tongue and lip, the
vocal cords and the walls of cysts, particularly those in connection with the breast and ovary.
Fibroma.—A true fibroma (containing only fibrous connective tissue) is rare. Most fibromas
are combined with other mesodermal tissues such as muscle (fibromyoma), fat (fibrolipoma),
and nerve sheaths (neurofibroma), etc. Multiple tumours are not uncommon, as, for example, in
neurofibromatosis (von Recklinghausen's disease).
Fibromas are either hard or soft, depending on the proportion of fibrous to the other cellular
tissue. Soft fibromas are common in the subcutaneous tissue of the face, and appear as soft
brown swellings.
Lipoma.—A lipoma is a slowly growing tumour composed of fat cells of adult type. Lipomas
may be encapsulated or diffuse. They occur anywhere in the body where fat is found and earn
the titles of the 'universal tumour' or the 'ubiquitous tumour'. The head and neck area,
abdominal wall, and the thighs are particularly favoured sites.
Encapsulated lipomas are among the commonest of tumours. The characteristic features are the
presence of a definite edge and lobulation. A sense of fluctuation may be obtained. As would be
expected, a lipoma deeply situated is liable to be mistaken for other swellings. Most lipomas are
painless, but some give rise to an aching sensation which may radiate.
Multiple lipomas are not uncommon. The tumours remain small or moderate in size, and are
sometimes painful, in which case the condition is probably one of neurolipomatosis. Dercum's
disease {adiposis dolorosa), characterised by tender deposits of fat, especially on the trunk, is
an associated condition.
Should the lipoma contain an excessive amount of fibrous tissue it is termed a fibrolipoma. In
other cases considerable vascularity is present, often with telangiectasis of the overlying skin, in
which case the tumour is a naevolipoma. Large lipomas of the thigh, the shoulder and the
retroperitoneum occasionally undergo sarcomatous changes. Myxomatous degeneration,
saponification and calcification sometimes occur in lipomas of long duration. Clinically,
circumscribed lipomas are classified according to their situation:
(1) Subcutaneous.—Commonly found on the shoulders or the back, although no part ot the
body is immune. A lipoma may be present over the site of a spina bifida. Subcutaneous lipomas
occasionally become pedunculated (lipoma arborescens).
(2) Subfascial.—Occurring under the palmar or plantar fascia, they are liable to be mistaken for
tuberculous tenosynovitis, as the tough, overlying fascia masks the definite edge and lobulation
of the tumour. Difficulty is encountered in complete removal as pressure encourages the tumour
to ramify. Subfascial lipomas also occur in the areolar layer under the epicranial aponeurosis,
and if of long duration they erode the underlying bone, so that a depression is palpable on
pushing the tumour to one side.
(3) Subsynovial.—From the fatty padding around joints, especially the knee. They are apt to be
mistaken for Baker's cysts but are easily distinguished as, in distinction to a cyst or bursa, their
consistency is constant whether the joint is in extension or flexion.
(4) Intra-anicular.
(5) Intermuscular.— Mainly in the thigh or around the shoulder. Owing to transmitted pressure
the tumour becomes firmer when the adjacent muscles are contracted. Weakness or aching
results, owing to mechanical interference with muscular action. The condition is often difficult
to distinguish from a fibrosarcoma.
(6) Parosteal occasionally occur under the periosteum of a bone.
(7) Subserous are sometimes found beneath the pleura, where they constitute one variety of
innocent thoracic tumour. A retroperitoneal lipoma may grow to enormous dimensions, and
simulate a hydronephrosis or pancreatic cyst.
(8) Submucous occur under the mucous membrane of the respiratory or alimentary tracts.
Rarely a submucous lipoma in the larynx causes respiratory obstruction. A submuc-ous lipoma
can occur in the tongue. One situated in the intestine is likely to cause an intussusception,
which is the first indication of its presence.
(9) Extradural.—A lipoma is a rare variety of spinal tumour. Owing to the absence of fat within
the skull intracranial lipomas do not occur.
(10) Intraglandular.—Lipomas have been found occasionally in the pancreas, under the renal
capsule and in the breast.
Treatment.—If a lipoma is causing trouble on account of its site, size, appearance, or the
presence of pain, removal is indicated.
During operation, any finger-like projections of the tumour into the surrounding tissue must
also be removed. Although the tumour is relatively avascular, care is needed to obtain complete
haemostasis in the resulting cavity—drainage often is necessary—otherwise a haematoma is
common, which may be followed by infection and delay in wound healing.
Diffuse lipoma occasionally occurs in the subcutaneous tissue of the neck, from which it
spreads on to the preauricular region of the face. The tumour is not obviously encapsulated, and
gives rise to no trouble beyond being unsightly.
Neuroma.—True neuromas are rare tumours, and occur in connection with the sympathetic
system. They comprise the following types:
(a) Ganglioneuroma, which consist of ganglion cells and nerve fibres. It arises in connection
with the sympathetic cord, and therefore is found in the retro-peritoneal tissue, or in the neck or
thorax.
(b) Neuroblastoma, which is less differentiated than the ganglioneuroma, the cells being of an
embryonic type. The tumour somewhat resembles a round-celled sarcoma, and disseminates by
the blood-stream. It occurs in infants and young children. It may occasionally undergo
spontaneous remission.
(c) Myelinic neuroma is very rare, being composed only of nerve fibres, as the ganglion cells
are absent. They arise in connection with the spinal cord or pia mater.
Neurilemmoma (syn. Schwannoma).—These lobulated and encapsulated tumours arise from the
neurilemmal cells. They are soft and whitish in appearance. They displace the nerve from
which they arise and can be removed.
Neurofibroma arise from the connective tissue of the nerve sheath. The following varieties are
described.
Local.—A single neurofibroma is usually found in the subcutaneous tissue. The 'painful
subcutaneous nodule' forms a smooth firm swelling which may be moved in a lateral direction,
but is otherwise fixed by the nerve from which it arises. Paraesthesia or pain is likely to occur
from the pressure of the tumour on the nerve fibres which are spread over its surface. Cystic
degeneration or sarcomatous changes occasionally occur.
Neurofibromas may also grow from the sheath of a peripheral nerve or a cranial nerve (e.g. the
acoustic tumour). As the nerve fibres are 'part and parcel' of the tumour they are difficult to
remove without removal of the nerve itself. In major nerves recurrence is known, also
malignant (sarcomatous) change.
Generalised Neurofibromatosis {syn. von Recklinghausen's Disease of Nerves).— In this
inherited (autosomal dominant) disease, any cranial, spinal or peripheral nerve may be diffusely
or nodularly thickened. The over-growth occurs in connection with the endoneurium.
Associated pigmentation of the skin is common, and sarcomatous changes may occur.
Plexiform Neurofibromatosis.—This rare condition usually occurs in connection with branches
of the fifth cranial nerve, although it may occur in the extremities . The affected nerves become
enormously thickened as a result of myxofibromatous degeneration of the endoneurium.
Elephantiasis Neuromatosa is a rare and congenital condition. The skin is coarse, dry, and
thickened, resembling an elephant's hide, and the subcutaneous tissues become greatly
thickened. If a leg is affected, the patient finds walking increasingly difficult.
False Neuroma—Arises from the connective tissue of the nerve sheath after injury to a nerve
(lacerations or amputation). These swellings consist of fibrous tissue and coiled nerve fibres.
Glomangioma (syn. Glomus Tumour.)—These tumours arise from a cutaneous glomus
composed of a tortuous arteriole which communicates directly with a venule, the vessels being
surrounded with a network of small nerves. These specialised organs regulate the temperature
of the skin, and are found in the limbs, especially the nail-beds. The tumour is compressible.
The associated pain is out of all proportion to the size of the tumour, which may be only a few
millimetres in diameter. The pain is burning in nature and radiates peripherally, and is more
often noticeable when the limb is exposed to sudden changes of temperature.
On section the tumour consists of a mixture of blood spaces, nerve tissue and muscle fibres
derived from the wall of the arteriole (angiomyoneuroma). Large cuboidal cells are frequently
seen (glomal cells). Cutaneous glomus tumours grow very slowly, and do not become
malignant. They should be excised.
Hamartoma.—The term hamartoma is roughly translated from the Greek' as a 'fault' or 'misfire'
or 'error' tumour, and its original meaning was 'missing the mark in spear throwing'. It is a
developmental malformation consisting of a tumour-like overgrowth of tissue or tissues proper
to the part. The possible range therefore is very wide, and the lesions are often multiple.
Common lesions that are hamartomas are benign pigmented moles, and the majority
ofangiomas and neurofibromas. On rare occasions a malignant change occurs in a hamartoma,
but for practical purposes the lesion is benign.
MALIGNANT TUMOURS
CARCINOMA AND SARCOMA
Carcinomas arise from cells which are ectodermal or endodermal in origin, and accordingly
they are classified squamous, basal-celled, or glandular. Sarcomas occur in connection with
structures of mesoblastic origin; hence fibrosarcoma, osteosarcoma.
Carcinoma
(1) Squamous arises from surfaces covered by squamous epithelium, particularly as a result of
chronic irritation. Also chronic irritation of transitional cells (e.g. by a stone in the renal pelvis)
or columnar cells (e.g. the gall bladder) will cause a change in these cells to a squamous type
(squamous metaplasia) and so lead on to carcinoma. The regional lymph nodes are likely to be
invaded, and may also be infected from the sepsis attendant upon the primary growth. Bloodborne metastases occur, but rarely from skin carcinoma.
Macroscopically, squamous-celled carcinomas are either proliferative or ulcerative. On section
solid masses of polyhedral cells are seen, which invade the deeper structures. 'Cell-nests' are
usually apparent in slowly growing cases, and are due to deeper cells becoming flattened and
undergoing kerarinisation. 'Prickle' (acanthotic) cells are characteristic, and resemble those
present in the epidermis.
(2) Basal-celled (syn. Rodent Ulcer).
(3) Glandular commonly occurs in the alimentary tract, breast and uterus, and less frequently in
the kidney, prostate, gall-bladder, and thyroid. The three types of glandular carcinoma are as
follows:
(a) Carcinoma simplex, in which the cells are arranged in circumscribed groups, no glandular
structure being recognisable. This type commonly occurs in the breast, and the majority of cells
are spheroidal or polygonal in shape.
(b) Adenocarcinoma, so called from the tendency of the cells to form acini, which resemble
those of the gland from which they are derived. The alveoli are ductless, and the walls are
composed of layers of cells which invade the surrounding tissues. The cells of the primary
growth, and even of the metastases, sometimes retain secretory powers.
(c) Colloid (mucoid) is a degenerative process which develops in tumours arising from mucinseeking cells. The mucin permeates the stroma of the growth, which appears as a gelatinous
mass and is typically seen in the colon and stomach. stomach.
Glandular carcinoma is also subdivided into various types, e.g. encephaloid, scirrhus and
atrophic scirrhus. These distinctions depend clinically on their rate of growth, and
pathologically on the relative proportions of fibrous tissue and gland elements.
Methods of Spread.—(1) Direct spread (local extension). Invasion takes place readily along
connective tissue planes, but no structures are resistant. Veins are invaded before arteries.
(2) Blood-stream. Cancer cells may be detected in the venous blood draining an organ involved
by carcinoma. A carcinoma of the kidney may invade the renal vein and grow inside the lumen
into the vena cava. Malignant emboli may be arrested in the lungs (secondary deposits—
metastases), but bizarre blood-borne deposits are not infrequently observed.
(3) Lymphatics by permeation and by embolism.
Lymphatic Permeation.—The malignant cells grow along the lymphatic vessels from the
primary growth. This may even occur in a retrograde direction. The cancer cells stimulate
perilymphatic fibrosis, but this does not stop the advance of the disease. In some instances,
notably malignant melanoma, groups of cells may so overcome the surrounding fibrosis, as to
give rise to intermediate deposits between the primary growth and the lymph nodes.
Lymphatic Embolism.—Cancer cells invade a lymphatic vessel and are carried by the lymph
circulation to a regional node, so that nodes comparatively distant from the tumour may be
involved in the early stages.
(4) Seeding.—Implantation of carcinoma has been observed in situations where skin or mucous
membrane is closely in contact with a primary growth. Examples of this ‘kiss cancer' are
carcinoma of the lower lip affecting the upper, and carcinoma of the labium majus giving rise to
a similar growth on the opposite side of the vulva. Recurrence after operation is occasionally
due to implantation of malignant cells in the wound. Examples of this mischance are the
appearance of a malignant deposit in the bladder scar after suprapubic removal of a primary
growth, and nodules of carcinoma in the scar of the incision after mastectomy. When the
peritoneum is involved, cells from a carcinoma may spread like snow-flakes all over its serous
surface. This transcoelomic spread is specially notable when cells from a colloid carcinoma of
the stomach gravitate on to an active ovary and give rise to malignant ovarian tumours
(Krukenberg's tumour.), which may be the first manifestation of gastric malignancy.
Grading and Staging.—Grading and staging are used to assess the degree of malignancy of the
tumour as an indication of the prognosis, and may be used as a guide to determine the type and
the extent of the treatment which is required.
TNM Classification. —This is a detailed clinical staging which is arrived at simply by the
clinician ascertaining the following points during his examination of the patient:
What is the extent of the primary Tumour? Are any lymph Nodes affected? Are there any
Metastases? The information so obtained is scored, for example in carcinoma of the breast, as
follows:
Tumour
Nodes
Metastasis
T1 = 2 cm or less.
No = No nodes.
Mo = No metastasis.
No skin fixation.
N1 = Axillary nodes
M1 = Metastases are
T2 = More than 2 cm,
movable (a) not
present including
but less than 5 cm.
significant, (b)
involvement of
Skin tethered or dimpled.
significant,
skin beyond breast, and
No pectoral fixation.
N2 = Axillary nodes fixed.
contralateral nodes.
T3 = More than 5 cm,
N3 = Supraclavicular nodes.
but less than 10 cm.
Oedema of arm
Skin infiltrated or ulcerated.
Pectoral fixation.
T4 = More than 10 cm.
Skin involved but not beyond
breast. Chest-wall fixation.
Thus, for example, one patient may have a carcinoma which is T1NoMo, while in another the
extent of the disease may be T2N2M1. This scoring can be applied easily to the commonly used
method of clinical stage grouping of carcinoma of the breast. Metastases present is equivalent
to Stage IV.
Sarcomas
Sarcomas differ from carcinomas, not only in their derivation, but in their age incidence, as
they are most common during the first and second decades. Sarcomas often grow with rapidity,
and dissemination occurs mainly by the bloodstream ('cannon-ball' secondary deposits in the
lung).
The macroscopic appearance of a sarcoma varies considerably. As the word implies, most
tumours appear as a fleshy mass, but their consistency depends on the relative proportion of
fibrous and vascular tissue. Haemorrhage commonly occurs owing to the very thin walls of the
veins, which in some places are represented merely by venous spaces.
Sarcomatous cells may reproduce tissue similar to that from which the tumour originated, e.g.
osteosarcoma or chondrosarcoma. Sometimes a sarcoma develops in pre-existing benign
tumours, such as fibroma or a uterine fibroid, and also in bones which are affected by osteitis
deformans .
Fibrosarcoma is composed of spindle cells of varying lengths (the rounder they are the more
malignant they are), and occurs in muscle sheaths, scars and as a fibrous epulis. A fibrosarcoma
of a muscle sheath presents as an elastic or firm and slowly growing swelling. Dilated veins
over the tumour suggest malignancy, and if not obvious they may be demonstrated by infra-red
photography. On palpation the tumour often feels warm and pulsation may even be detected.
Recurrent Fibroid.—Fibrosarcomas not uncommonly arise in scar tissue, sometimes many
years after the scar developed.
Treatment of Fibrosarcoma.—The spread of a sarcoma is hastened by incomplete removal. The
moral is that wide excision with surrounding healthy tissues should
be practised in all cases. This may mean amputation in the case of a limb. If wide local
excision is unsuccessful, or if untreated, a fibrosarcoma eventually fungates through the skin.
Metastases are widely scattered, and, unfortunately, radiotherapy has but little effect on either
the primary growth or on the secondary deposits.
Lymphomas arise in lymph nodes, tonsils, Peyer's patches or lymph nodules in the intestines.
Lymph nodes of the neck or mediastinum are most commonly affected.
Synovioma.—This rather uncommon tumour may arise in any synovial joint or tendon sheath,
especially those of the hand. It appears as a soft, painless swelling, and sarcomatous changes
can occur. The diagnosis can only be established by excision and biopsy of the tumour.
Endothelioma. Mesothelioma.—The endothelial linings of blood-vessels, lymphatic spaces and
serous membranes occasionally give rise to neoplasms. They can be malignant. They arise from
the pleura and rarely from the pericardium or peritoneum. The original cells are flattened, but
they become spheroidal or cuboidal when neoplastic changes occur. The 'endothelioma'
(meningioma) of the dura mater is thought to arise from the arachnoid membrane, which is not
an endothelial structure.
Peritheliomas are tumours arising in the endothelial lining of small blood-vessels or
lymphatics. Carotid body tumours are probably of this nature.
BENIGN - MALIGNANT
Certain innocent neoplasms are prone to undergo malignant changes, and it is important, both
for treatment and prognosis, to realise when this occurs. Some or all of the following changes
may be recognised:
(1) Increase in size—comparatively rapid enlargement is always suspicious, e.g. a neurofibroma
which is becoming sarcomatous.
(2) Increased vasularity—dilated cutaneous veins, ulceration and bleeding in the case of a
superficial growth (e.g. melanoma).
(3) Fixity—due to invasion of surrounding structures.
(4) Involvement of adjacent structures—Facial palsy suggests a malignant change in an
otherwise longstanding parotid pleomorphic adenoma.
(5) Dissemination—discovery of secondary deposits is occasionally the clue to the development
of malignancy.
To confirm the diagnosis of a malignant lesion or its metastases special investigations
have to be performed:
Endoscopy.
Cytology (swabs, aspirates).
Histology (biopsy).
X-ray investigations (roentgenoscopy, roentgenography, tomography, angiography,
lymphography).
Radioisotope methods (scanning, scinti graphy).
Ultrasonography.
Computerised axial tomography.
Laboratory tests (blood cell morphology, enzyme activity etc, as indicated).
One of the crucial points in evaluating the patient suspected of having a malignant
disease is the staging of the tumour, for this helps decide on the appropriate management.
According to the clinical classification, the four stages of pathological overgrowth are
identified:
Stage I — tumour is localised, occupies a limited area, does not infiltrate into the wall
of the organ, metastases are absent.
Stage II — tumour is of a big size, can infiltrate into the organ wall but does not spread
beyond the organ, there can be solitary metastases to the regional lymph nodes.
Stage III — tumour is of a big size with degeneration, infiltration into the hollow organ
wall; multiple metastases to the regional lymph nodes are present.
Stage IV — tumour with distant metastases to organs and lymph nodes and with
infiltration of surrounding organs.
The TNMGP classification
Characteristics to be
Abbreviation Stands for
Stages
considered
T
N
T1 -T4
Tumour
Nodes
Size of the primary tumour
NO - nodes are not palpable
Involvement of the lymph N1 - metastases to the regional
nodes
nodes
N2 - metastases to the second
level nodes
N3 - metastases to distant
nodes
M
G
Metastases
Grade
Presence of organ
metastases
Tumour differentiation
MO - no metastases
M1 - metastases present
G1
- low level of malignancy
(highly differentiated
tumour)
G2 - moderate level of
malignancy (low differentiated tumour)
G3 - high
level of
malignancy (undifferentiated
tumour)
P
Penetra-
Depth of the tumourous
P1 - cancer infiltrating into the
mucous membrane
tion
infiltration into the walls of P2 - cancer infiltrating into the
a hollow organ (histological
submucosal layer
criteria)
P3 - cancer infiltrating ito as deep
as the serous layer
P4 - cancer infiltrating into the
serous layer or extending beyond the organ wall
GENERAL PRINCIPLES OF TUMOUR TREATMENT
The malignant diseases call for immediate therapy, whereas benign masses require
treatment if they
cause dysfunction of the organ affected;
result in cosmetic defects;
are found premalignant;
• are suspected of transforming into malignant ones.
The therapeutic methods for malignant disease include surgery, radiation, chemo- and/or
hormone therapy.
Surgery is the main method of treatment of malignant tumours and it is often combined with radiation or chemotherapy. This is referred to as combined therapy (for example, in breast cancer,
cancer of the uterus, ovaries, etc.). The radiation therapy can be either employed pre- or
postoperatively. This can also accompany chemotherapy, as is the case, for example, in
myeloma or Hodgkin's lymphoma.
Surgery is not applied if the condition can be treated by radiation or drug therapy alone (e.g. cancer of the lip).
When the tumour has advanced so far that successful surgery in view of a metastatic spread is
very unlikely, the case is considered inoperable.
Operating on patients with malignant tumours, the surgeon should follow the principle of
ablasty, which implies the prevention of spread of tumour cells during the surgery by means of
removing the mass within the intact tissues. To avoid damaging the tumour, it is necessary to
ligate the veins as early and excise the tumour, fat tissues and lymph nodes en bloc.
The principle of antiblasty involves:
the measures aimed at destroying the cancer cells in the operation site (in the wound, in the lymph
vessels and veins using electrocautery, laser or plasmatic scalpels;
cleansing the wound after excision of the tumour with 70% alcohol solution;
regional infusions of chemotherapeutic drugs.
As the tumour cells can spread beyond the organ affected to the lymphatic vessels, lymph nodes
and surrounding tissues, it is recommended that a large portion or the entire organ involved be
removed together with the surrounding tissues and fasciae. This is known as the principle of
zones. An operation for breast cancer serves as an illustration, in which case the breast with the
fatty tissues, fasciae and the subclavial, axillary lymph nodes as well as the pectoralis major
muscles is removed en bloc.
The radical operation involves the removal of the entire organ (e.g. the breast, uterus) or its large
portion (the stomach, bowel) together with the regional lymph nodes.
The combined surgery during which the organ affected is excised with part of or the entire
organ into which the tumour has spread is also regarded radical.
Palliative operations are performed to remove part or the entire organ if the metastases are not
liable to ablation. They are indicated when complications of the malignancy are found (e.g.
tumour decay with bleeding, perforation of gastric or colonic cancer).
Symptomatic operations are aimed at eliminating complications caused by the enlarged
tumour without removing the tumour itself (e.g. gastrostomy in oesophageal cancer; interintestinal anastomosis in bowel cancers complicated by intestinal obstruction, tracheostomy in
cancer of the larynx).
Radiation therapy. Above half of the patients with malignant tumours are exposed to
radiotherapy. It can either be used as an independent method for early stages of the disease (e.g.
cancer of the lower lip, cervix of the uterus and the skin) or is included in the combined
therapy. Radiation therapy is commonly coupled with surgery and undertaken either pre- or
postoperatively. In addition, radiotherapy can be combined with chemo- or hormone therapy.
The curative effect on the tumour and its metastases is achieved through external, intra-cavitary
or interstitial radiation.
External radiation involves g-therapy with radioisotopes ("Co, "'Cs, etc.).
In intracavitary radiation therapy the source of radiation is introduced into a natural cavity (e.g.
the oral cavity or uterine cavity, urinary bladder, maxillary antrum etc.). To perform interstitial
radiation, isotopes are inserted directly into the tissues using needles or capsules after the
removal of the tumour (e.g. postmastectomy). Staying in the tissues for long periods the
isotopes act on the residual tumour cells and their metastases to the lymph nodes.
Chemotherapy. The most common malignant tumours (e.g. cancers of the lung, breast, stomach
and intestines) are known to respond poorly to drug therapy as compared to surgical and radiation
therapy. Hence, the use of chemotherapy in combination with other methods of treatment.
If combined with surgery, chemotherapy is employed to treat, for instance, ovarian cancer.
Also, it is of great importance for the treatment of systemic oncological diseases (e.g.
leukaemia, Hodgkin's lymphoma). At the early stage of malignancy, i.e. when the tumour can
be removed surgically, chemotherapy alone should not be attempted.
The following groups of chemotherapeutic preparations are used:
1. Cytostatics (novembihin, cyclophosphan, TEPA [triethylenethiophospharamide], dopan,
vinblastin, vincristin, etc.) hamper the growth of tumour cells, affecting cellular mitosis.
2. Antimetabolites alter the metabolism of cancer cells by suppressing the synthesis of purins
(mercaptopurin); acting on the enzyme systems (fluoruracil, phthorafur) or on the
transformation of folic acid (metotrexate).
3. Anti-cancer antibiotics are a group of compounds produced by fungi or microorganisms:
actinomycin D, bruneomycin, mytomycin.
Hormone therapy. Hormones are a treatment of choice for hormone receptor-positive tumours.
These medications supplement the combined therapeutic methods of surgery, radiotherapy and
chemotherapy. The preparations of the male sex hormone — androgen (testosterone propionate,
methyl testosterone) are indicated in breast cancer, whereas those of female sex steroid - estradiol
(synestrol and diethylstilboestrol) are known to be effective in cancer of the prostate.
Hormone therapy of tumours also includes surgeries on the endocrine glands e.g. surgical or
radiation castration of women with breast cancer.