Radiation-Associated Rectal Cancer: Report of Four Cases

Abstract

Background/Aims: Radiation-associated rectal cancer is a remarkable clinical entity. We demonstrate 4 patients (mean age 68 years, range 63–74) who had undergone pelvic radiotherapy for cervical cancer. We indicate some characteristics of radiation-associated rectal cancer. Results: Two patients had received intracavitary and external pelvic radiotherapy, while the remaining 2 had external pelvic radiotherapy following hysterectomy. The mean total radiation dose was 63 Gy, though radiation dose information was not available for 1 patient. Colorectal cancer developed at a mean time of 20.7 years (range 11–30) after radiation therapy. All patients presented with chronic radiation colitis, and 3 demonstrated abnormal tumor markers. Colonoscopy revealed an ulcerative, localized well-differentiated adenocarcinoma of the rectosigmoid colon in 1 patient, and diffusely infiltrating cancers of the lower rectum, one signet-ring cell carcinoma and two mucinous carcinomas in the remaining 3. One case was stage I, 2 were stage IIIa, and the remaining case was stage IV. Three patients underwent abdominoperineal resection. The remaining patient was felt to be inoperable. The colorectal wall demonstrated the changes of chronic radiation injury. Two patients died within a short time because of their advanced cancers. Conclusion: Radiation-associated rectal cancer has a tendency to be diagnosed in the advanced stage and to have a poor prognosis. A literature review and our case report suggest that since there are no reliable clinical or laboratory indicators of the presence of a curable colorectal cancer in the setting of chronic radiation proctocolitis, surveillance with a colonoscope should be done 10 years after irradiation in patients with previous pelvic radiotherapy.

Antioxidant Properties of Probiotics and Their Protective Effects in the Pathogenesis of Radiation-Induced Enteritis and Colitis

“…The incidence of rectal bleeding ranges between 1 and 20% [58]. Importantly, CRC is a precancerous lesion: Radiationassociated secondary rectal cancer originates mainly from the direct functional effects of ionizing radiation (such as point mutations) to the DNA and the following dysplasia and has a tendency to be diagnosed at an advanced stage and to bear a dismal prognosis [59]. In summary, ARE and ARC are common side-effects of abdominopelvic radiotherapy and usually transient with symptomatic management without interruption of radiation therapy treatments.…”

Recent advances in the management of radiation colitis

“…Since radiotherapy is now being used more than ever before in the therapy of solid organ neoplasms of the abdomen and the pelvis, the incidence of radiation colitis is likely to increase in the future [24][25][26] . Importantly, it is a precancerous lesion: Radiation-associated rectal cancer originates from dysplasia due to radiation colitis and has a tendency to be diagnosed at an advanced stage and to bear a dismal prognosis [27,28] . Therefore, management of chronic radiation colitis remains a major challenge owing to the progressive evolution of the disease that includes development of fibrosis, endarteritis, edema, fragility, perforation, partial obstruction, and even cancer.…”

Inflammation Enhanced X-irradiation-Induced Colonic Tumorigenesis in the Min mouse

“…This risk was reported to be proportional to dose and volume of radiation; tumors were more likely localized in an irradiated segment of the colon (Nottage et al, 2012). Radiotherapy is a powerful tool for the treatment of gynecological malignancies including cervical (Tamai et al, 1999) and endemetrial cancers (Brown et al, 2010) and prostate cancer (Bolla et al, 2013). Patients treated with radiotherapy likely have significantly increased risk of subsequent primary malignancies including bladder, vagina, colon, and soft-tissue (Brown et al, 2010).…”