Real-life experiences and barriers to adjuvant chemotherapy in Saudi patients with advanced stage II and stage III colon cancer

BACKGROUND

Colorectal cancer is the most common malignancy in Saudi males and third most common in females. Patients with locally advanced colon cancer may eventually develop metastatic disease if not treated promptly and according to guidelines. The recent National Comprehensive Cancer Network guideline recommends tumor resection followed by adjuvant chemotherapy for stage III and high-risk stage II tumors. Therefore, the objective of this study was to characterize patients with locally advanced colon cancer and identify factors associated with the use of adjuvant chemotherapy and the addition of oxaliplatin in locally advanced colon cancer patients.

METHODS

All patients diagnosed with locally advanced colon cancer at National Guard Health Affairs (NGHA) during 2016-2021 were investigated. Patients' characteristics were compared using Chi-square and Fisher exact test, whereas predictors of adjuvant chemotherapy/Oxaliplatin use were identified using univariate and multivariate logistic regression.

RESULTS

Out of 222 patients diagnosed with locally advanced colon cancer, 133 received adjuvant chemotherapy. Factors associated with adjuvant chemotherapy administration were age and smoking status. In the multivariable analysis, older patients were less likely to receive oxaliplatin than younger patients. Stage III patients diagnosed during 2019-2021 had 5.61 times higher odds of receiving oxaliplatin.

CONCLUSION

The findings of this study show that older patients and smokers are less likely to be treated with adjuvant chemotherapy. Moreover, age as well as diagnosis year were important determinants of oxaliplatin administration in stage III locally advanced colon cancer patients.

Treatment selection bias for chemotherapy persists in colorectal cancer patient cohort studies even in comprehensive propensity score analyses

Introduction

Propensity score methods are increasingly used to address confounding related to treatment selection in observational studies. Studies estimating the effect of chemotherapy in colon cancer (CC) patients, however, often lacked information on pertinent comorbidities and functional status (FS). We assessed to what extent comorbidities and FS impact treatment decisions in colorectal cancer patients and explain the benefit of chemotherapy in stage III CC patients.

Methods

Stage II-III colorectal cancer patients diagnosed in 2003-2014 and recruited into a population-based study were included (N=1102). Associations of comorbidity and FS with treatment patterns were examined with multivariable logistic regression. The contribution of lower comorbidity and higher FS to the benefit of chemotherapy was estimated with propensity score weighted Cox models in 430 stage III CC patients who were followed over a median time of 4.7 years.

Results

In stage II (high-risk) and III CC patients, Charlson comorbidity scores 1, 2 and 3+ were associated with 57%, 66% and 70% lower odds of chemotherapy use, respectively. In combination with older age and poor FS, comorbidity was associated with 97% and 83% decreased odds of adjuvant chemotherapy use in CC and rectal cancer patients, respectively. In stage III CC patients, lower comorbidity and higher FS explained 38% and 24% of the overall and disease-specific survival benefits of chemotherapy, respectively. Selection bias was observed even in the comprehensive models, as chemotherapy was still associated with substantially higher non-disease-specific survival (hazard ratio (HR): 0.66; 95% confidence interval (CI): 0.46-0.92), especially in patients <75 years (HR: 0.33; 95% CI: 0.17-0.63).

Conclusion

Lower comorbidity and higher FS of recipients of chemotherapy explain approximately 40% of the benefits of chemotherapy in stage III CC patients. Regardless of how comprehensive propensity score analyses might be in observational studies, treatment selection bias might persist and affect estimates of treatment effects.

Real-world data: towards achieving the achievable in cancer care

The use of data from the real world to address clinical and policy-relevant questions that cannot be answered using data from clinical trials is garnering increased interest. Indeed, data from cancer registries and linked treatment records can provide unique insights into patients, treatments and outcomes in routine oncology practice. In this Review, we explore the quality of real-world data (RWD), provide a framework for the use of RWD and draw attention to the methodological pitfalls inherent to using RWD in studies of comparative effectiveness. Randomized controlled trials and RWD remain complementary forms of medical evidence; studies using RWD should not be used as substitutes for clinical trials. The comparison of outcomes between nonrandomized groups of patients who have received different treatments in routine practice remains problematic. Accordingly, comparative effectiveness studies need to be designed and interpreted very carefully. With due diligence, RWD can be used to identify and close gaps in health care, offering the potential for short-term improvement in health-care systems by enabling them to achieve the achievable.

Delivery of adjuvant chemotherapy among stage III colon cancer patients at a public versus private hospital in New York City

PURPOSE

Prior studies of timeliness of adjuvant chemotherapy (AC) initiation in stage III colon cancer have suggested longer time to AC at public compared with private hospitals. Few studies have explored differences in AC completion. We investigated whether timely initiation and completion of AC differed between a public and private hospital, affiliated with the same academic institution in a large, urban setting.

METHODS

We conducted a retrospective cohort study of stage III colon cancer patients who had surgery and AC at the same medical center between 2008 and 2015, either at its affiliated public hospital (n = 43) or private hospital (n = 79). We defined timely initiation as receiving AC within 60 days postoperatively, and completion as receiving ≥ 75% of planned AC. Univariate and stepwise multivariable logistic regressions were used to identify factors associated with AC delivery.

RESULTS

Median number of days to AC was significantly greater among patients at the public (53, range 31-231) compared with the private hospital (43, range 25-105; p = 0.002). However, the percentage of patients with timely AC initiation did not differ substantially by hospital (74 vs 81%, p = 0.40). In multivariable analysis, age (OR 0.95/year, 95% CI 0.91-0.99) and laparoscopic versus open surgery (OR 5.65, 95% CI 1.92-16.62) were significant factors associated with timely AC initiation. Moreover, AC completion did not differ significantly between public (83.7%) and private (89.9%) hospital patients (p = 0.32).

CONCLUSIONS

The proportions of patients with timely initiation and completion of AC were similar at a public and private hospital affiliated with a large, urban medical center. Future research should investigate how specific system-level factors help alleviate this expected difference in timely care delivery.

Management of stage III colon cancer in the elderly: Practice patterns and outcomes in the general population

BACKGROUND

Clinical trials have established surgical resection and adjuvant chemotherapy (ACT) as the standard management for stage III colon cancer; however, the extent to which these results apply to elderly patients in routine practice is unclear. This article describes the management and outcomes of elderly patients with stage III colon cancer.

METHODS

All cases of surgically resected colon cancer from 2002 to 2008 were identified with the population-based Ontario Cancer Registry. Pathology reports were obtained for a random sample (25% of all cases); those with stage III disease constituted the study population. The utilization of ACT, cancer-specific survival (CSS), and overall survival (OS) in elderly patients (≥70 years) and nonelderly patients (<70 years) were compared.

RESULTS

The study population included 2920 patients, and 1521 (52%) were elderly. The 30- and 90-day mortality rates increased with advanced age: <70 years, 2% and 5%; 70 to 74 years, 3% and 7%; 75 to 79 years, 5% and 8%, and ≥80 years, 9% and 16% (P < .001). ACT was delivered to 48% of elderly patients and to 81% of younger patients (P < .001). Factors independently associated with ACT utilization among the elderly were a younger age (P < .001), male sex (P = .041), and no comorbidities (P = .001). Among elderly patients, ACT was associated with improved CSS (hazard ratio [HR], 0.73; 95% confidence interval [CI], 0.60-0.88) and OS (HR, 0.71; 95% CI, 0.60-0.83); however, the magnitude of the benefit was smaller for elderly patients than younger patients (HR for CSS, 0.53; 95% CI, 0.42-0.67; HR for OS 0.56; 95% CI, 0.45-0.69).

CONCLUSIONS

Half of elderly patients with stage III colon cancer do not receive ACT. Although the effect size is smaller than that in younger patients, ACT is associated with improved long-term survival. Cancer 2017;123:2840-49. © 2017 American Cancer Society.