Adjuvant chemotherapy for stage C colonic cancer in a multidisciplinary setting

Association Between Adjuvant Chemotherapy Duration and Survival Among Patients With Stage II and III Colon Cancer: A Systematic Review and Meta-analysis

IMPORTANCE

The results from the recent International Duration Evaluation of Adjuvant Therapy (IDEA) collaboration have led some clinicians to adopt shorter durations of adjuvant chemotherapy for patients with stage III colon cancer. The extent to which these findings are supported by other data is unknown.

OBJECTIVE

To conduct a systematic review and meta-analysis of randomized and observational studies investigating the association between the duration of adjuvant chemotherapy and survival among individuals diagnosed as having stage II and III colon cancer (PROSPERO protocol CRD42018108711]).

DATA SOURCES

Abstracts published in English between 2003 and 2018 within the MEDLINE, Embase, CENTRAL, and CINAHL databases were reviewed by 2 authors. Also searched were conference proceedings and the indexes of high-impact oncology journals.

STUDY SELECTION

Studies were excluded if they did not present original data; focused on animal populations, on cancers in sites other than the colon, or on patients with stage 0, I, or IV disease; did not examine a 5-flourouracil-based monotherapy or combination therapy; or did not evaluate the association between treatment duration and survival. The search identified 2341 articles, from which 2 randomized trials and 20 observational studies were included in the meta-analysis.

DATA EXTRACTION AND SYNTHESIS

This study followed the PRISMA and MOOSE reporting guidelines. The risk of bias was assessed by 2 authors using the Cochrane and Risk of Bias in Nonrandomized Studies of Interventions (ROBINS-I) tools. The results were synthesized using a random-effects model.

MAIN OUTCOMES AND MEASURES

The primary and secondary outcomes were overall survival and disease-free survival, respectively. It was hypothesized a priori that 3 months of chemotherapy would be as effective as 6 months of chemotherapy.

RESULTS

Twenty-two studies were included in the meta-analysis, representing 43 671 patients. The inclusion of patients with stage II disease or with rectal cancer was identified as a source of heterogeneity. After restricting the analysis to patients with stage III colon cancer, there was no association between the duration of chemotherapy and overall survival among studies involving FOLFOX (leucovorin calcium [folinic acid], fluorouracil, and oxaliplatin) or CAPOX (capecitabine plus oxaliplatin) regimens (hazard ratio [HR], 0.80; 95% CI, 0.58-1.09). Among studies focused exclusively on monotherapy, the standard 6-month regimen relative to a 3-month regimen was associated with improved survival (HR, 0.59; 95% CI, 0.52-0.68).

CONCLUSIONS AND RELEVANCE

Shortened durations of chemotherapy may reduce survival among patients with stage III colon cancer prescribed monotherapy but not a combination regimen.

Comparative economics of a 12-gene assay for predicting risk of recurrence in stage II colon cancer

BACKGROUND

Prior economic analysis that compared the 12-gene assay to published patterns of care predicted the assay would improve outcomes while lowering medical costs for stage II, T3, mismatch-repair-proficient (MMR-P) colon cancer patients. This study assessed the validity of those findings with real-world adjuvant chemotherapy (aCT) recommendations from the US third-party payer perspective.

METHODS

Costs and quality-adjusted life-years (QALYs) were estimated for stage II, T3, MMR-P colon cancer patients using guideline-compliant, state-transition probability estimation methods in a Markov model. A study of 141 patients from 17 sites in the Mayo Clinic Cancer Research Consortium provided aCT recommendations before and after knowledge of the 12-gene assay results. Progression and adverse events data with aCT regimens were based on published literature. Drug and administration costs for aCT were obtained from 2014 Medicare Fee Schedule. Sensitivity analyses evaluated the drivers and robustness of the primary outcomes.

RESULTS

After receiving the 12-gene assay results, physician recommendations in favor of aCT decreased 22 %; fluoropyrimidine monotherapy and FOLFOX recommendations each declined 11 %. Average per-patient drugs, administration, and adverse events costs decreased $US2,339, $US733, and $US3,211, respectively. Average total direct medical costs decreased $US991. Average patient well-being improved by 0.114 QALYs. Savings are expected to persist even if the cost of oxaliplatin drops by >75 % due to generic substitution.

CONCLUSIONS

This study provides evidence that real-world changes in aCT recommendations due to the 12-gene assay are likely to reduce direct medical costs and improve well-being for stage II, T3, MMR-P colon cancer patients.

Use of adjuvant chemotherapy in stage C (III) rectal cancer: comparison of data from matched patients in a teaching hospital's clinico-pathological database

AIMS

Controversy continues regarding the treatment of patients with resectable rectal cancer, particularly in regard to the effects of adjuvant therapies on long-term survival. The benefits of adjuvant chemotherapy alone in patients with stage III rectal cancer after curative resection remain unclear. The aim of this study was to compare the overall survival of patients who had received adjuvant chemotherapy after resection of a stage III rectal cancer (111 patients) with the survival of a historical control group who had surgery alone before chemotherapy was introduced (129 patients).

METHODS

Treatment and outcomes data were drawn from a prospective hospital registry of consecutive patients who had a resection for stage III rectal cancer.

RESULTS

The estimated Kaplan-Meier overall 5-year survival rate in patients who received chemotherapy (68.7%, 95% CI 58.3-77.1%, log-rank P < 0.001) was improved compared with the historical controls (40.5%, 95% CI 31.4-49.5%, log-rank P < 0.001). No systematic differences between the treated and control group were found.

CONCLUSION

This study has shown improved survival after adjuvant chemotherapy in patients with stage III rectal cancer as compared with historical controls treated by surgery alone. Hence, there could be subsets of patients whom when treated with surgery in a specialized surgical unit, may benefit from chemotherapy and spared the toxicities of adjuvant radiotherapy. This should be explored further in a cooperative trial group setting.

Glutathione S-transferase Pi expression predicts response to adjuvant chemotherapy for stage C colon cancer: a matched historical control study

Background

This study examined the association between overall survival and Glutathione S-transferase Pi (GST Pi) expression and genetic polymorphism in stage C colon cancer patients after resection alone versus resection plus 5-fluourouracil-based adjuvant chemotherapy.

Methods

Patients were drawn from a hospital registry of colorectal cancer resections. Those receiving chemotherapy after it was introduced in 1992 were compared with an age and sex matched control group from the preceding period. GST Pi expression was assessed by immunohistochemistry. Overall survival was analysed by the Kaplan-Meier method and Cox regression.

Results

From an initial 104 patients treated with chemotherapy and 104 matched controls, 26 were excluded because of non-informative immunohistochemistry, leaving 95 in the treated group and 87 controls. Survival did not differ significantly among patients with low GST Pi who did or did not receive chemotherapy and those with high GST Pi who received chemotherapy (lowest pair-wise p = 0.11) whereas patients with high GST Pi who did not receive chemotherapy experienced markedly poorer survival than any of the other three groups (all pair-wise p <0.01). This result was unaffected by GST Pi genotype.

Conclusion

Stage C colon cancer patients with low GST Pi did not benefit from 5-fluourouracil-based adjuvant chemotherapy whereas those with high GST Pi did.