Adjuvant chemotherapy of colon cancer current strategies

A principled machine learning framework improves accuracy of stage II colorectal cancer prognosis

Accurate prognosis is fundamental in planning an appropriate therapy for cancer patients. Consequent to the heterogeneity of the disease, intra- and inter-pathologist variability, and the inherent limitations of current pathological reporting systems, patient outcome varies considerably within similarly staged patient cohorts. This is particularly true when classifying stage II colorectal cancer patients using the current TNM guidelines. The aim of the present work is to address this problem through the use of machine learning. In particular, we introduce a data driven framework which makes use of a large number of diverse types of features, readily collected from immunofluorescence imagery. Its outstanding performance in predicting mortality in stage II patients (AUROC = 0:94), exceeds that of current clinical guidelines such as pT stage (AUROC = 0:65), and is demonstrated on a cohort of 173 colorectal cancer patients.

The Effect of Adjuvant Chemotherapy on Stoma-Related Complications After Surgery for Colorectal Cancer: A Retrospective Analysis

PURPOSE

To assess stoma-related complications of colorectal cancer patients undergoing surgery with curative intent who received adjuvant chemotherapy compared to those who underwent surgery alone.

DESIGN

A retrospective analysis of a prospectively maintained colorectal cancer clinical audit database was completed.

SUBJECTS AND SETTINGS

Patients undergoing curative surgery for colorectal cancer with the formation of a stoma (end ileostomy, loop ileostomy, end colostomy) between 1999 and 2011 at a single hospital in Lanarkshire, United Kingdom. Patients who underwent neo-adjuvant chemotherapy were excluded. Two hundred twenty-two patients comprised the study sample; 130 (59%) were male. Seventy-five (34%) patients comprised the chemotherapy group and 147 (66%) made up the surgery-only group. Patients in the chemotherapy group were younger (61.6 vs 65.4 years; P = .001) and had higher stage colorectal cancer (P < .001). There was no difference in baseline (day 10) stoma scores between the chemotherapy or surgery-only groups.

METHODS

Postoperative stoma-related complications were serially assessed using a stoma complication scoring tool; scores were calculated at 10 days and 3 months postoperatively. Scores of patients receiving adjuvant chemotherapy were compared to scores of participants who underwent surgery alone.

INSTRUMENT

A composite stoma function score was calculated for each patient after assessment of stoma-related complications. The overall score included a global assessment of stoma quality (stoma retraction, prolapse, stenosis, parastomal hernia, skin changes) and patient-reported stoma function (leakage, soiling, nighttime emptying, odor).

RESULTS

At 3 months, the mean loop ileostomy stoma function score was poorer among the chemotherapy group when compared to the surgery-only group (4.55 vs 1.53; P = .041). No differences were found when colostomy (2.00 vs 2.62; P = .411) or end ileostomy (1.00 vs 2.00; P = .170) function scores were compared at 3 months.

CONCLUSION

Patients undergoing curative surgery for colorectal cancer resulting in a loop ileostomy who received adjuvant chemotherapy had higher stoma complication scores at 3 months compared to those who underwent surgery with no chemotherapy. This difference was not seen in patients with colostomies or end ileostomies. Patients, WOC nurses, and medical staff must be alert to the potential of increased loop ileostomy-related complications with adjuvant chemotherapy. Fully informed patient consent coupled with timely support and advice may reduce stoma-related morbidity and improve quality of life for such patients.

Biological predictors of survival in stage II colorectal cancer

The routine use of postoperative adjuvant chemotherapy in patients with stage II colorectal cancer is not recommended. However, the incidence of tumor recurrence or distant metastasis in these patients is reported to be 25–35%. The identification of high-risk patients with stage II colorectal cancer remains difficult. Therefore, the aim of this study was to determine the risk factors that may help identify stage II colorectal cancer patients with unfavorable prognosis. Paraffin-embedded tissue samples from 109 patients with stage II colorectal cancer following curative operation were analyzed. Thirteen clinicopathological variables and 5 biological markers were assessed using immunohistochemistry, including p53 (tumor suppressor gene), CD10 (tumor invasion marker), CD34 (angiogenic marker), Ki-67 (cell proliferation index) and CAM 5.2 (marker of lymph node micrometastasis) and investigated for associations with disease-specific survival. Univariate analysis revealed bowel obstruction, lymph node micrometastasis and lymphatic invasion (P<0.01) to be highly significant factors for determining the 5-year disease-specific survival. By contrast, the multivariate analysis revealed lymph node micrometastasis and lymphatic invasion to be independent prognostic factors. Stage II colorectal cancer patients with lymph node micrometastasis and lymphatic invasion may therefore be suitable candidates for adjuvant chemotherapy to improve prognosis.

Adjuvant colon cancer chemotherapy: where we are and where we'll go

Many patients with early-stage colon cancer are cured with surgery alone, even if the standard of care remains an uniform approach to adjuvant chemotherapy based primarily on tumour stage. Consequently, it is important to individualize decision-making in this subset of patients with the aim to identify potential prognostic and predictive markers in colon cancer. While 5-fluorouracil, leucovorin, and oxaliplatin are widely known as gold treatment in the post-operative of stage III, well-validated molecular markers might help define which patients with stage II disease are likely to benefit from adjuvant therapy as well. Herein we review the use of adjuvant chemotherapy in colon cancer and analyzed the date on the clinical development of molecular markers to individualize another therapeutic approach in colon cancer.