Survival rates overall for cancer patients are higher now than 20 years ago, though younger patients are faring significantly better than older ones for many types of cancer, according to investigators.
The findings were published online Feb. 19 in JAMA Oncology.
Furthermore, racial disparities in survival persist for most cancer sites, wrote Chenjie Zeng and associates at Vanderbilt University, Nashville, Tenn.
Using data from the National Cancer Institute Surveillance, Epidemiology, and End Results (SEER) Program, the researchers calculated survival rates for just over a million patients diagnosed with cancer of the colon or rectum, breast, prostate, lung, liver, pancreas or ovary over the time span from 1990 to 2009. Survival rates were obtained for each cancer site; results were grouped in 5-year cohorts by diagnosis date, and further broken down by race, sex, and age group (20-49, 50-64, 65-74, and 75-85 years at time of diagnosis).
Hazard ratios for cancer-specific death were obtained by comparing all later 5-year cohorts to the 1990-1994 group. Adjusted HRs for patients aged 50-64 years diagnosed with cancer in 2005-2009 compared with those diagnosed in 1990-1994 were 0.57 for colon or rectal cancer, 0.48 for breast cancer, 0.61 for liver cancer, and 0.32 for prostate cancer. By contrast, the oldest patients (aged 75-85 years) had HRs of 0.88, 0.88, 0.76, and 0.65, respectively, for these cancer sites. Age-related findings were less pronounced for lung and pancreatic cancers, Ms. Zeng and associates said (JAMA Oncology 2015 Feb. 19 [doi:10.1001/jamaoncol.2014.161]).
African Americans had a greater increase in prostate cancer survival than did whites or Asians; ovarian cancer survival, however, was reduced for African Americans but improved among whites over the study period. Overall survival rates were poorer for all cancer sites for African Americans when compared to whites, with racial disparities in screening and care a potential factor.
Some of the age-related survival differences may be attributed to younger patients’ being able to take greater advantage of newer therapies, since the largest age-related survival gap occurred for cancer sites with greater treatment advances (breast, colorectal, and prostate cancers), Ms. Zeng and associates said.
Study limitations included inability to exclude potential confounders such as socioeconomic status, lifestyle choices, and comorbidities, as well as oversampling of urban and foreign-born individuals in the study population, the researchers noted.