Medical staff at David Grant USAF Medical Center perform thoracoscopic surgery to remove the upper left lobe in a lung cancer patient at the heart, lung and vascular center, Travis Air Force Base, CA. U.S. Air Force photo by Heide Couch
BETHESDA, MD — Small-cell lung cancer patients receiving universal healthcare access, as in the U.S. military, had longer survival rates than similar patients in the U.S. general population, according to a new study.
The report in Annals of Epidemiology called for more research to identify factors that could contribute to improved survival.1
Researchers from the John P. Murtha Cancer Center Research Program, Uniformed Services University of the Health Sciences and Walter Reed National Military Medical Center, all in Bethesda, MD, took a close look at lung cancer care in the U.S. military health system (MHS).
Noting that it was unknown whether the provision of universal healthcare access translates into improved patient outcomes. To help answer that question, the study team compared survival of SCLC patients in the MHS with that in the U.S. general population. Researchers also assessed stage and receipt of cancer treatment to see if those factors contributed to the survival differences.
The study used data from both the DoD’s Automated Central Tumor Registry (ACTUR) and the national Surveillance, Epidemiology, and End Results (SEER) program, which includes the general U.S. population.
The 3,040 ACTUR and 12,160 SEER patients were matched on age, sex, race and diagnosis year.
Results indicated that ACTUR patients had significantly better survival than SEER counterparts (HR = 0.77, 95% CI= 0.71-0.83). Researchers pointed out that ACTUR and SEER patients were at similar cancer stages, but ACTUR patients were more likely to receive radiation treatment (OR=1.26, 95% CI=1.12-1.42).
Still, they added, the survival advantage of ACTUR patients remained across all tumor stages and radiation groups.
SCLC accounts for approximately 15% of bronchogenic carcinomas, according to the National Cancer Institute, and the prognosis, in general, for those patients is suboptimal.
NCI pointed out that, at the time of diagnosis, about 30% of SCLC patients have tumors confined to the hemithorax of origin, the mediastinum or the supraclavicular lymph nodes—considered to be limited-stage disease (LD). When tumors spread beyond the supraclavicular areas, that is considered extensive-stage disease (ED).
Although SCLC is more responsive to chemotherapy and radiation therapy than other cell types of lung cancer, according to public health officials, achieving a cure is extremely difficult because SCLC tends to be widely disseminated by the time of diagnosis.
Overall incidence and mortality rates of SCLC in the United States have decreased during the past few decades, according to the NCI. Risk factors, many of which are more likely in military servicemembers and veterans, are similar to those for non-small cell lung cancer:
- History of or current tobacco use: cigarettes, pipes and cigars.
- Exposure to cancer-causing substances in secondhand smoke.
- Occupational exposure to asbestos, arsenic, chromium, beryllium, nickel and other agents.
- Radiation exposure from any of the following:
- Radiation therapy to the breast or chest.
- Radon exposure in the home or workplace.
- Medical imaging tests, such as computed tomography (CT) scans.
- Atomic bomb radiation.
- Living in an area with air pollution.
- Family history of lung cancer.
- Human immunodeficiency virus infection.
- Beta carotene supplements in heavy smokers.
Treatment Options
Treatment options for SCLC patients are determined by histology, stage and general health and comorbidities of the patient. A key issue is differentiating it from NSCLC, according to the National Cancer Institute.
“Regardless of stage, the current prognosis for patients with SCLC is unsatisfactory despite improvements in diagnosis and therapy made during the past 25 years,” according to the NCI website. “Without treatment, SCLC has the most aggressive clinical course of any type of pulmonary tumor, with median survival from diagnosis of only two to four months. About 10% of the total population of SCLC patients remains free of disease during the two years from the start of therapy, which is the time period during which most relapses occur.”
If added that even those patients remain at risk of dying from lung cancer, with overall five-year survival of 5% to 10% (i.e., patients with LD have a better prognosis than patients with ED).
For patients with LD, median survival of 16 to 24 months and five-year survivals of 14% with current forms of treatment can occur. A key factor is that continued smoking might compromise survival. Chemotherapy combined with thoracic radiation therapy (TRT) is considered the standard of care, with TRT increasing absolute survival by about 5% over chemotherapy alone.
On the other hand, in patients with ED, median survival of six to 12 months is reported with currently available therapy, although long-term disease-free survival is rare, the NCI pointed out.
- Lin J, Kamamia C, Brown DW, Shao S, McGlynn KA, Nations JA, Carter CA, Shriver CD, Zhu K. Comparative study of survival among small cell lung cancer patients in the U.S. military health system and those in the surveillance, epidemiology, and end results (SEER) program. Ann Epidemiol. 2021 Sep 20;64:132-139. doi: 10.1016/j.annepidem.2021.09.010. Epub ahead of print. PMID: 34547444.
