Download Lung Cancer Pathology Lung cancer is the growth of malignant cells

Lung Cancer
Pathology
Lung cancer is the growth of malignant cells in the lungs. These cells eventually form tumors that can easily
spread (metastasizing) to other tissues in the body, before the tumors are even detectable, because they have
extremely easy access to both the circulatory and lymph systems. Lung cancer is an example of epithelial cancer
that tends to grow where tissue is vulnerable to repeated irritation and damage. Cigarette smoking causes more
than 8 out of 10 cases of lung cancer, and accounts for a majority of the cases, is one of the most preventable
types of cancer.(1, 2)
Lung cancer is the leading cause of cancer death among men and women in Canada. In 2008, there was an
estimated 23,000 new diagnoses of lung cancer and 20,200 Canadian deaths which account for approximately
15% of cancer diagnoses and 29% of all cancer deaths, as researched by the Canadian Cancer Society.(2)
The anatomy of the lungs is that they occupies all the thoracic cavity except for the mediastinum but is the rootsite of vascular and bronchial attachment to mediastinum. The costal surface are the anterior, lateral, and
posterior surfaces. The lungs are composed primarily of alveoli. The apex of the lungs are the superior tip; deep
to the clavicle, base is inferior and rests on the diaphragm, and the hilum is on the mediastinal surface. It is the
site for entry/exit of the blood vessels, bronchi, lymphatic vessels and nerves. The left lung is smaller than the
right. It has a cardiac notch meaning it has a concavity for the heart. It is separated into superior and inferior
lobes by the oblique fissure. The right lung is separated into superior, middle, inferior lobes by the oblique and
horizontal fissures. There are smaller divisions called bronchopulmonary segments (10 for the right and 8-10 for
the left) that are separated by connective tissue septa. If one of these segments get diseased it can be
individually removed. Lastly the lobules are the smallest subdivisions visible to the naked eye. They are served
by the bronchioles and their branches.
The physiology of the lungs is the workings of the lungs. The mechanics of breathing into the lungs is the
pulmonary ventilation that consists of two phases-inspiration: gases flowing into the lungs and -expiration:
gases exiting the lungs. The relationships of pressure in the thoracic cavity have to be either have to be greater
or less than that of the atmospheric pressure that is exerted by the air surrounding the body for breathing to
occur.
Types
Some different types of lung cancer include, small cell lung cancer also called ‘oat cell’ carcinoma and this
accounts for 20% of lung cancers. This cancer grows fast, spreads quickly and is rarely operable. There is also
non-small cell lung cancer and this accounts for 85% of lung cancers. With this cancer, depending on which
cells they affect first, can include several types like squamous cell carcinoma, adenocarcinoma, large cell
carcinoma and several others. Most of this cancers grow more slowly than small cell carcinoma but the
symptoms they produce are so subtle that diagnosis doesn’t happen until long after the cancer has spread
beyond its original area. Then lastly other types of lung malignancies that are not as common as small cell and
non-small cell lung cancers but have been identified as well. Such as carcinoid tumors, adenoid cystic
carcinoma, sarcomas and others. One other cancer that falls under this category that closely associated with
asbestos exposure is mesothelioma and it arises in the pleural sac that surrounds the lung.(1)
Signs and Symptoms
For the signs and symptoms of lung cancer, there are two stages. Stage one is probably one of the hardest to
identify in the early onset of lung cancer. Some early signs may be a persistent smoker’s cough (occurs when
the person attempts to dislodge the tumour in the lungs), bloodstained phlegm or sputum (occurs when the
cough damages the tumour), chronic chest pain, wheezing and possibly shortness of breath may be some
indicters of lung cancer. These can go unnoticed by doctors because a smoker or someone who works with
irritating chemicals often have them regardless of the health of their respiratory tract cells. As for stage two, this
is where the later signs of lung cancer come into play. Where the tumour grows may mimic other health
problems like if a tumour grows near the apex of the lung, this can put mechanical pressure on the brachial
plexus, mimicking symptoms of thoracic outlet syndrome (TOS). If a tumour that presses on the superior vena
cava may cause facial swelling and dilated blood vessels in the neck and face, and this is called superior vena
cava syndrome. A person can have chronic hoarseness if a tumour protrudes on the esophagus or larynx. Lastly
if a tumour press on the phrenic nerve can cause paralysis of the diaphragm.(1, 3)
Causes and Risk Factors
Possible causes of lung cancer are asbestos, radon, uranium, arsenic, air pollution, chromium, benzene,
cadmium, nickel, coal tar and lastly, that makes up for 85-90% of all lung cancer cases, cigarette, pipe and or
cigar smoking.(1, 3)
People who are at risk of developing lung cancer are cigarette smokers, pipe smokers and cigar smokers, also
people who inhale second hand smoke are also at risk of developing lung cancer but not to the same degree as
someone who smokes.(3)
Treatment
To treat lung cancer the doctors can either do surgery, radiation or chemotherapy. Surgery is performed if the
tumour is located. Those who do have it done (30-35% of the people), are doing well five years after treatment.
With the surgery they can do a wedge resection where the doctors remove a small section of lung tissue, a
lobectomy where the doctors remove an entire lobe or a pneumonectomy where the doctors remove the entire
lung. If a person is unable to tolerate surgery or the tumour can’t be removed safely or the cancer is growing
and spreading to fast to be removed, then the doctors can do radiation to treat the cancer. Chemotherapy is often
the one doctors use to treat cancer cells in the body if the cancer has metastasized.(1, 3)
Targeted therapies for lung cancer include the use of biologically engineered antibodies that deliver drugs or
radiation to cancer cells. Drugs that interfere with angiogenesis, drugs that inhibit cancer cell growth factors,
drugs that make cancer cells sensitive to light, and a cancer ‘vaccine’ that essentially introduces a substance that
makes the immune system cells more sensitive to cancer cells. All of these are still in experimental use and they
all carry serious potential side effects, but they may eventually be both more effective and less risky than
traditional cancer treatments. Then there are medications to ameliorate the side effects of the chemotherapy. (1)
Massage
Massage for someone with lung cancer can be beneficial because it can be a supportive strategy for a person
going through this challenging time. It can also help with insomnia, pain, fatigue, anxiety, and depression-all of
which can make both the cancer and side effects of the medication seem worse. Massage risks the therapist
should look out for are the type of treatment the cancer patient is undergoing like chemotherapy, radiation and
surgery all have specific cautions for massage. If the cancer patient is nearing the end of their journey in life and
is seeking strictly palliative care then the therapist should adjust the bodywork for frailty, the risk of problems
with bones or major organs and any medical equipment that can be disrupted.(1)
References
1. Werner, Ruth (Ruth A.)
A massage therapist’s guide to pathology/Ruth Werner
P 351-352
2. Porth pathophysiology: concepts of altered health states/[edited by] Ruth A. Hannon…[et al.].-1st
Canadian ed.
p.659-662
3. Rattray, Fiona S. (Fiona Scott), 1958Clinical Massage Therapy: Understanding, Assessing and Treating Over 70 Conditions
p.1030-1031