Effect of Age on Survival Benefit of Adjuvant Chemotherapy in Elderly Patients with Stage III Colon Cancer

Abstract Background: Adjuvant chemotherapy is relatively underused in older patients with colon cancer in Japan, and its age-specific effects on clinical outcomes remain unclear. This study aimed to assess the effect of adjuvant chemotherapy on survival benefit in stage III colon cancer patients stratified by age in a Japanese real-world setting. Methods: In this multi-center retrospective cohort study, we analyzed patient-level information through a record linkage of population-based cancer registry data and administrative claims data. The study population comprised patients aged ≥18 years who received a pathological diagnosis of stage III colon cancer and underwent curative resection between 2010 and 2014 at 36 cancer care hospitals in Osaka Prefecture, Japan. Patients were divided into two groups based on age at diagnosis (<75 and ≥75 years). The effect of adjuvant chemotherapy was analyzed using Cox proportional hazards regression models for all-cause mortality with inverse probability weighting of propensity scores. Adjusted hazard ratios were estimated for both age groups. Results: A total of 783 patients were analyzed; 476 (60.8%) were aged <75 years and 307 (39.2%) were aged ≥75 years. The proportion of older patients who received adjuvant chemotherapy (36.8%) was substantially lower than that of younger patients (73.3%). In addition, the effect of adjuvant chemotherapy was different between the age groups: the adjusted hazard ratio was 0.56 (95% confidence interval: 0.33-0.94, P=0.027) in younger patients and 1.07 (0.66-1.74, P=0.78) in older patients. Conclusions: The clinical effectiveness of adjuvant chemotherapy in older patients with stage III colon cancer appears limited under current utilization practices.

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Effect of adjuvant chemotherapy on survival benefit in stage III colon cancer patients stratified by age: a Japanese real-world cohort study

10.21203/rs.2.13960/v3 ◽

2019 ◽

Author(s):

Hidetaka Kawamura ◽

Toshitaka Morishima ◽

Akira Sato ◽

Michitaka Honda ◽

Isao Miyashiro

Keyword(s):

Colon Cancer ◽

Cohort Study ◽

Adjuvant Chemotherapy ◽

Cancer Patients ◽

Survival Benefit ◽

Older Patients ◽

Age Groups ◽

Stage Iii ◽

Younger Patients ◽

Stage Iii Colon Cancer

Abstract Background: Adjuvant chemotherapy is relatively underused in older patients with colon cancer in Japan, and its age-specific effects on clinical outcomes remain unclear. This study aimed to assess the effect of adjuvant chemotherapy on survival benefit in stage III colon cancer patients stratified by age in a Japanese real-world setting. Methods: In this multi-center retrospective cohort study, we analyzed patient-level information through a record linkage of population-based cancer registry data and administrative claims data. The study population comprised patients aged ≥18 years who received a pathological diagnosis of stage III colon cancer and underwent curative resection between 2010 and 2014 at 36 cancer care hospitals in Osaka Prefecture, Japan. Patients were divided into two groups based on age at diagnosis (<75 and ≥75 years). The effect of adjuvant chemotherapy was analyzed using Cox proportional hazards regression models for all-cause mortality with inverse probability weighting of propensity scores. Adjusted hazard ratios were estimated for both age groups. Results: A total of 783 patients were analyzed; 476 (60.8%) were aged <75 years and 307 (39.2%) were aged ≥75 years. The proportion of older patients who received adjuvant chemotherapy (36.8%) was substantially lower than that of younger patients (73.3%). In addition, the effect of adjuvant chemotherapy was different between the age groups: the adjusted hazard ratio was 0.56 (95% confidence interval: 0.33-0.94, P=0.027) in younger patients and 1.07 (0.66-1.74, P=0.78) in older patients. Conclusions: The clinical effectiveness of adjuvant chemotherapy in older patients with stage III colon cancer appears limited under current utilization practices.

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Effect of adjuvant chemotherapy on survival benefit in stage III colon cancer patients stratified by age: a Japanese real-world cohort study

10.21203/rs.2.13960/v1 ◽

2019 ◽

Author(s):

Hidetaka Kawamura ◽

Toshitaka Morishima ◽

Akira Sato ◽

Michitaka Honda ◽

Isao Miyashiro

Keyword(s):

Colon Cancer ◽

Cohort Study ◽

Adjuvant Chemotherapy ◽

Cancer Patients ◽

Survival Benefit ◽

Older Patients ◽

Age Groups ◽

Stage Iii ◽

Younger Patients ◽

Stage Iii Colon Cancer

Abstract Background: Adjuvant chemotherapy is relatively underused in older patients with colon cancer in Japan, and its age-specific effects on clinical outcomes remain unclear. This study aimed to assess the effect of adjuvant chemotherapy on survival benefit in stage III colon cancer patients stratified by age in a Japanese real-world setting. Methods: In this multi-center retrospective cohort study, we analyzed patient-level information through a record linkage of population-based cancer registry data and administrative claims data. The study population comprised patients aged ≥18 years who received a pathological diagnosis of stage III colon cancer and underwent curative resection between 2010 and 2014 at 36 cancer care hospitals in Osaka Prefecture, Japan. Patients were divided into two groups based on age at diagnosis (<75 and ≥75 years). The effect of adjuvant chemotherapy was analyzed using Cox proportional hazards regression models for all-cause mortality with inverse probability weighting of propensity scores. Adjusted hazard ratios were estimated for both age groups. Results: A total of 783 patients were analyzed; 476 (60.8%) were aged <75 years and 307 (39.2%) were aged ≥75 years. The proportion of older patients who received adjuvant chemotherapy (36.8%) was substantially lower than that of younger patients (73.3%). In addition, the effect of adjuvant chemotherapy was different between the age groups: the adjusted hazard ratio was 0.56 (95% confidence interval: 0.33-0.94, P =0.027) in younger patients and 1.07 (0.66-1.74, P =0.78) in older patients. Conclusions: The clinical effectiveness of adjuvant chemotherapy in older patients with stage III colon cancer appears limited under current utilization practices.

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Reasons for and outcomes of adjuvant chemotherapy choices in elderly patients with resected stage III colon cancer.

Journal of Clinical Oncology ◽

10.1200/jco.2012.30.4_suppl.571 ◽

2012 ◽

Vol 30 (4_suppl) ◽

pp. 571-571 ◽

Cited By ~ 1

Author(s):

Jenny Ko ◽

Hagen F. Kennecke ◽

Howard John Lim ◽

Sharlene Gill ◽

Ryan Woods ◽

...

Keyword(s):

Colon Cancer ◽

Adjuvant Chemotherapy ◽

Adjuvant Therapy ◽

Elderly Patients ◽

Cancer Patients ◽

Treatment Effect ◽

Advanced Age ◽

Stage Iii ◽

Stage Iii Colon Cancer ◽

To Receive

571 Background: Research suggests that elderly cancer patients are commonly undertreated, but the precise reasons for this are unclear. Robust clinical data on the optimal adjuvant chemotherapy regimen for elderly colon cancer patients are also lacking. Our aims were to: 1) evaluate the impact of advanced age on choice of adjuvant chemotherapy (none vs. capecitabine vs. FOLFOX) for curatively resected colon cancer; b) determine the reasons for selecting a particular regimen; and 3) examine whether treatment effect on outcomes is modified by age. Methods: All patients diagnosed with stage III colon cancer between 2006 and 2008, and referred to any 1 of 5 regional cancer centers in British Columbia, Canada were identified. Descriptive statistics were used to summarize treatment patterns among young patients (YPs) aged <70 years vs. elderly patients (EPs) aged >/=70 years. Multivariate logistic regression models were constructed to evaluate the association between adjuvant chemotherapy and cancer-specific survival (CSS) in YPs and EPs. Results: In total, 810 patients were identified: 51% were male, 52% YPs and 48% EPs, and 74% received adjuvant chemotherapy. When compared to YPs, EPs had worse ECOG and more comorbidities (both p<0.001). EPs were less likely than YPs to receive adjuvant chemotherapy (57% vs. 91%, p<0.001). Frequent reasons for no treatment included age, comorbidities, and small perceived benefit from adjuvant therapy. Among treated pts, EPs were less likely to receive FOLFOX (32% vs. 74%, p<0.0001) in favor of capecitabine due to patient preference, age, and comorbidities. In multivariate analyses, receipt of either FOLFOX or capecitabine was correlated with improved CSS compared to surgery alone. The effect of adjuvant chemotherapy on CSS was not modified by age (interaction p for capecitabine and age = 0.26; interaction p for FOLFOX and age = 0.40). Conclusions: EPs with stage III colon cancer frequently received either no adjuvant treatment or capecitabine monotherapy due to advanced age and co-morbidities. The treatment effect of adjuvant therapy on CSS is similar among EPs and YPs. Adjuvant chemotherapy should not be withheld from colon cancer patients based on advanced age alone.

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