Young and middle-aged patients with colon cancer are 2 to 8 times more likely to receive post-operative chemotherapy than older patients, yet study results suggest no added survival benefit for these patients.
Colorectal cancer is the third leading cause of cancer death in the US, with an expected 134,490 new cases and 49,190 deaths in 2016. While incidence and mortality rates among adults 50 years and older have decreased in the US in recent years, the same trend has not been observed for patients 20 to 49 years of age. Treatment options for patients with young-onset colon cancer remain to be defined and their effects on prognosis are unclear.
Dr Kangmin Zhu, of the John P Murtha Cancer Centre, Walter Reed National Military Medical Centre, and colleagues examined whether age differences in receiving chemotherapy matched survival gains among patients diagnosed as having colon cancer in an equal-access health care system. The study was based on data from the US Department of Defence’s Central Cancer Registry and Military Heath System medical claims databases. There were 3,143 patients ages 18 to 75 years with histologically confirmed primary colon cancer diagnosed between 1998 and 2007.
Of the patients, 59% were men. Young (18-49 years) and middle-aged (50-64 years) patients were two to eight times more likely to receive postoperative systemic chemotherapy compared with older patients (65-75 years), regardless of tumour stage at diagnosis. Young and middle-aged adults were 2.5 times more likely to receive multi-agent chemotherapy regimens. While young and middle-aged adults who only underwent surgery had better survival compared with older patients, no significant differences in survival were seen between young/middle-aged and older patients who received surgery plus postoperative systemic chemotherapy.
“Most of the young patients received post-operative systemic chemotherapy, including multi-agent regimens, which are currently not recommended for most patients with early-stage colon cancer. Our findings suggest over-treatment of young and middle-aged adults with colon cancer,” the authors write.
Abstract
Importance: Treatment options for patients with young-onset colon cancer remain to be defined and their effects on prognosis are unclear.
Objective: To investigate receipt of adjuvant chemotherapy by age category (18-49, 50-64, and 65-75 years) and assess whether age differences in chemotherapy matched survival gains among patients diagnosed as having colon cancer in an equal-access health care system.
Design, Setting, and Participants: This cohort study was based on linked and consolidated data from the US Department of Defence’s Central Cancer Registry and Military Heath System medical claims databases. There were 3143 patients aged 18 to 75 years with histologically confirmed primary colon adenocarcinoma diagnosed between 1998 and 2007. This study was conducted from December 2015 to August 2016.
Exposures: Patients who underwent surgery and postoperative systemic chemotherapy.
Main Outcomes and Measures: The primary outcome measure of the study was overall survival of patients who only received surgery and those who received both surgery and postoperative systemic chemotherapy.
Results: Of the 3143 patients, 1841 were men (58.6%). Young (18-49 years) and middle-aged (50-64 years) patients were 2 to 8 times more likely to receive postoperative systemic chemotherapy compared with older patients (65-75 years) across all tumor stages. Middle-aged patients with stage I (odds ratio, 5.04; 95% CI, 2.30-11.05) and stage II (odds ratio, 2.42; 95% CI, 1.58-3.72) disease were more likely to receive postoperative chemotherapy compared with older patients. Both groups were more likely to receive multiagent chemotherapy than were older patients (patients aged 18-49 years: odds ratio, 2.48; 95% CI, 1.42-4.32 and patients aged 50-64 years: odds ratio, 2.66; 95% CI, 1.70-4.18). Among patients who received surgery and postoperative systemic chemotherapy, no significant differences were observed in survival among age groups (the 95% CIs of hazard ratios included 1 for young and middle-aged patients compared with older patients for all tumor stages).
Conclusions and Relevance: In an equal-access health care system, we found potential overuse of chemotherapy among young and middle-aged adults with colon cancer. The addition of postoperative systemic chemotherapy did not result in matched survival improvement.
Authors
Janna Manjelievskaia; Derek Brown; Katherine A McGlynn; William Anderson; Craig D Shriver; Kangmin Zhu
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