DeCure for Rectum cancer

In a ten-year series of 252 selected patients with carcinoma of the rectum for whom conservative treatment was advocated, 211 were treated conservatively and followed for eight to 18 years; the procedure was successful in 96.2 per cent of cases and failed or partially failed in 3.8 per cent. In an additional 41 patients, radical operation was performed despite conservative treatment being recommended, and examination of the surgical specimen showed that 40 of the 41 could have been treated by conservative means on the basis of Dukes' classification. A separate series reported that diathermy treatment of rectal cancer was valuable as palliation, and local treatment was used with apparent success as a curative procedure in 30 patients who had no contraindication to more radical surgery, although spontaneous regression did not occur in that series. A 1978 Japanese study of 196 cases of cancer of the colon and rectum after curative resection concluded the disease is curable if discovered and resected at stage I, where cancerous proliferation is limited to the proper muscle layer without metastasis.

A 2023 retrospective study of 96 colorectal cancer patients with carcinomas in the sigmoid colon, rectosigmoid junction, and rectum found no difference in clinicopathologic characteristics among the three groups. TP53, APC, and KRAS were the top three altered genes in all locations. Rates of KRAS, NRAS, and PIK3CA increased as the location moved distally, while rates of APC and BRAF decreased. Almost no significant molecular differences were found among the three groups; the prevalence of FLT3, FLT1, and PCK1 mutations was lower in the rectosigmoid junction group than in the sigmoid colon and rectum groups, but with P values above 0.05. The transforming growth factor beta pathway proportion was higher in the rectosigmoid junction and rectum groups than in the sigmoid colon group (39.3 per cent vs. 34.3 per cent vs. 18.2 per cent, respectively, P=0.121, P=0.067, P=0.682), and a higher proportion of MYC pathway was observed in the rectosigmoid junction than in rectum and sigmoid colon (28.6 per cent vs. 15.2 per cent vs. 17.1 per cent, P=0.278, P=0.202, P=0.171). Regardless of clustering method, patients divided into two clusters with no significant differences in composition by location; the authors concluded that rectosigmoid junction cancer has a distinctive molecular profile compared to adjacent bowel segment cancers.

A cDNA microarray study of 21 rectal cancer patients identified 23 genes up-regulated and 15 genes down-regulated in at least five samples, with hierarchical cluster analysis classifying patients into two groups according to clinicopathological stage, one group all above stage II and one all below stage II. A 2018 Spanish-language review notes that in colorectal cancer, prognosis depends on local tumour involvement, regional lymph node metastasis, lymphovascular invasion, positive surgical margins, preoperative carcinoembryonic antigen elevation, and tumour grade, but response to treatment remains difficult to predict in specific scenarios, particularly metastatic stage. A 2006 review states cancer of the rectum makes up 4 to 6 per cent of all malignant lesions in humans and that growth of the disease is marked in many countries.

A 1968 paper on cancer of the rectum concludes that progress in overall control can be accomplished by achieving the highest possible resectability rate, well-designed surgical procedures, employment of adjuncts available then and continued efforts to find more effective agents, detection and removal of polyps, earlier diagnosis, clinical research in immunology, cooperative pooling of data, long-term follow-up of large populations, and epidemiologic studies; it also discourages regressive measures that threaten effective available treatments. What remains missing across these studies is prospective validation of the molecular classifications in larger cohorts, standardised criteria for selecting patients for conservative versus radical treatment, and any evidence from randomised trials comparing local treatment with surgery; the molecular data are retrospective and underpowered, with no significant differences reaching conventional thresholds.