Download Abstract Introduction Methods SEER

Effectiveness of Photodynamic Therapy in Patients with
Non-Small Cell Lung Cancer: A Population Based Study
Ravishankar Jayadevappa, PhD., Department of Medicine, Sumedha Chhatre, PhD., Department of Psychiatry
University of Pennsylvania, Philadelphia PA 19008, USA
Abstract
Background: In USA, there will be 224,390 estimated new cases of
lung cancer in 2016 and 158,080 deaths due to lung cancer. Lung cancer
accounts for about 27% of all cancer deaths and is the leading cause of
cancer death. Non-small cell lung cancer (NSCLC) constitutes about 8590% of all lung cancer cases.
Objective: To analyze the time to follow-up, sequence of treatment, cost,
and mortality in NSCLC patients treated with photodynamic therapy (PDT)
or non-PDT ablation therapy.
Methods: Data source: The Surveillance, Epidemiology and End Results
(SEER)-Medicare data are the linkage of two large population-based
sources of data in the USA and provide detailed information about
Medicare beneficiaries with cancer. Currently, the SEER program of
National Cancer Institute collects data on cancer incidence, treatment
and mortality from eighteen SEER sites and encompasses 26% of the
population of the USA. Study cohort: Patients with NSCLC diagnosed
between 2000 and 2011 were identified and retrospectively followed for
one-year pre and up to ten-year post diagnosis. We analyzed the
proportion of treatment that occurred during phases of care and
sequence of PDT treatment. Primary outcome was time to follow-up
surgery or radiation therapy, after PDT or non-PDT ablation therapy. Time
to treatment, variation in health service use and cost were compared
between PDT and non-PDT ablation groups using GLM, Poisson (Zero
inflated), and GLM-log link models respectively. All analysis was
adjusted for following covariates: Age, race, marital status, gender,
geographic region, stage, and comorbidity. Propensity score approach
was used to minimize selection bias.
Results: Of the NSCLC cohort of 359,608, 136 received PDT with other
treatments, and 1405 received non-PDT ablation with other treatments.
In PDT group, 66% and in non-PDT ablation group, 75% of the treatment
was within one-year of NSCLC diagnosis. Unadjusted mean time to
follow-up treatment was 235 days (SD 566) for PDT group and 147 days
(SD 382) for non-PDT ablation group. After adjusting for demographic
and clinical variables, PDT was associated with an average increase of
80 days in time to follow-up treatment (p=0.0253) compared to non-PDT
ablation group. Compared to radiation alone, PDT group showed lower
hazard of overall five year mortality (HR= 0.64, CI= 0.53, 0.77). PDT was
associated with 38% increase in cost, compared to non-PDT ablation
group (p=0.0014).
SEER-Medicare Linked
Database
Table 2: Clinical Characteristics
The Surveillance, Epidemiology and End Results
(SEER) - Medicare data are the linkage of two
large population-based sources of data and
provide detailed information about Medicare
beneficiaries with cancer in the USA.
Currently, the SEER program of National Cancer
Institute collects data on cancer incidence,
treatment and mortality from eighteen SEER sites
and encompasses 26% of the population of the
USA.
Analysis
*Significant at 0.05 level
 Comparison of demographic and clinical
variables between four treatment groups: PDT
(alone or multimodal), non- PDT ablation (alone
or multimodal), radiation therapy with chemo
and radiation therapy alone.
 ANOVA for mean survival time, and time to
follow-up treatment.
 GLM log-link regression for cost analysis.
Results
Introduction
 Among PDT group, 66% and in non-PDT
ablation group, 75% of the treatment was
within one-year of NSCLC diagnosis.
 Study Design: Retrospective case control
design.
 Data source: Surveillance, Epidemiology and
End Results (SEER) - Medicare Linked
Database.
 Study sample: Persons diagnosed with
NSCLC between 2000-2011.
 Two phases of disease were defined: one year
of pre-diagnosis phase & up to thirteen years
of treatment/follow-up phase.
 Outcome variables: Survival, time to follow-up
treatment and cost of care.
 Cost of care was operationalized as
reimbursement from Medicare.
 Covariates: Age, race, marital status, gender,
geographic region, stage, and comorbidity.
Table 4: Comparison of
Unadjusted Cost
 Cox proportional hazard analysis for survival.
 Of the NSCLC cohort of 359,608, 136
received PDT with other treatments, and 1405
received non-PDT ablation with other
treatments.
Methods
Table 3: Comparison of
Unadjusted Survival Time
Of persons aged 65 years and older, diagnosed
with cancer and enrolled in SEER registries, 93%
have a match in Medicare enrollment records.
Conclusion: PDT was associated with longer time to follow-up treatment
compared to non-PDT ablation in NSCLC patients. Currently, PDT is
offered in various combinations with surgery and radiation. This demands
larger studies to investigate the efficacy and effectiveness of these
combinations.
 In USA, there are 224,390 estimated new
cases of lung cancer and 158,080 deaths due
to lung cancer in 2016.
 Lung cancer accounts for about 27% of all
cancer deaths and is the leading cause of
cancer death.
 Non-small cell lung cancer (NSCLC)
constitutes about 85-90% of all lung cancer
cases.
Objective:
 To analyze the time to follow-up treatment,
sequence of treatment, cost, and mortality in
NSCLC patients treated with photodynamic
therapy (PDT) or non-PDT ablation therapy.
*Significant at 0.05 level
*Significant at 0.05 level
Figure 1:
Survival by Treatment Groups
Compared to other treatments, PDT group
showed lower hazard of overall five year
mortality (HR= 0.64, CI= 0.53, 0.77).
Log-Rank p <.0001
 Unadjusted mean time to follow-up treatment
was 235 days (SD 566) for PDT group and
147 days (SD 382) for non-PDT ablation
group.
 After adjusting for demographic and clinical
variables, PDT was associated with an
average increase of 80 days in time to followup treatment (p=0.0253) compared to nonPDT ablation group. Compared to radiation
alone, PDT group showed lower hazard of
overall five year mortality (HR= 0.64, CI= 0.53,
0.77).
Figure 2:
Time to Follow-Up Treatment
Unadjusted mean time to follow-up
treatment was 235 days (SD 566) for PDT
group and 147 days (SD 382) for non-PDT
ablation group.
Log-Rank p <.0001
 PDT was associated with 38% increase in
cost, compared to non-PDT ablation group
(p=0.0014) among US SEER-Medicare
patients.
Table 1:
Demographic Characteristics
Radiation alone,
(n=77,994)
PDT (alone or
multimodal,
n=136)
Non-PDT ablation
(alone or
multimodal,
n=1405)
Radiation with
chemo
(n=56,700)
73.8 (9.2)
70.6 (7.9)
70.9 (8.8)
71.8 (7.8)
78.5
82.3
80.7
80.6
African
American
11.9
8.8
13.0
10.6
Hispanic
4.0
2.2
3.1
3.7
Other
5.6
6.6
3.2
5.1
Married* (%)
51.1
57.9
55.1
58.4
Male* (%)
56.8
59.6
57.9
57.2
Mean age at diagnosis
(s.d.)*
Ethnicity* (%) White
*Significant at 0.05 level
Conclusions
 PDT was associated with longer time to followup treatment compared to non-PDT ablation in
NSCLC patients. Currently, PDT is offered in
various combinations with surgery and radiation.
This demands larger studies to investigate the
efficacy and effectiveness of these
combinations.
 Future research should address the
comparative effectiveness to understand the
ultimate clinical implications of PDT therapy for
NSCLC patients.
Acknowledgement: Supported by the Pinnacle Biologics
Research/Educational Grant
Disclosure: No conflict of interest to disclose