International Journal of Radiation Oncology*Biology*Physics
Clinical investigationAnal canalRadiochemotherapy in the conservative treatment of anal canal carcinoma: Retrospective analysis of results and radiation dose effectiveness
Introduction
Cancer of the anal canal is uncommon, accounting for approximately 1–2% of all large-bowel cancers and 4% of all anorectal cancers (1, 2). However, because of higher spreading of human papilloma virus and human immunodeficiency virus (HIV) through sexual transmission, there has been a marked incidence of this disease over the last two decades (2). Before 1974, the conventional treatment for anal canal cancer was abdominoperineal resection (APR). This therapeutic approach has undergone dramatic changes since the publication by Nigro et al. (3). Their preliminary report stated that 3 patients who had been submitted to a combination of preoperative radiation therapy with 30 Gy, 5-fluorouracil (5-FU), and mitomycin C (MMC) had a complete response at the time of APR. Based upon this experience, several trials were developed with combined radiochemotherapy alone, keeping surgery for salvage.
A number of trials have demonstrated that this combined modality treatment yields a complete response rate of approximately 80–90%, associated with a high rate of sphincter preservation, local control, and survival. Nevertheless, its acute toxicity is relatively high, and the ideal dose of radiation has yet to be defined. This retrospective analysis intends to report results on patients with anal canal carcinoma treated with radiotherapy (RT) combined with chemotherapy (CT) based on 5-FU and MMC, as well as the analysis of some prognostic factors and effectiveness of the radiation dose.
Section snippets
Patients
Between March 1993 and December 2001, 43 patients with squamous cell carcinoma of the anal canal were treated at the Hospital do Câncer A.C. Camargo with associated radiotherapy and chemotherapy. Clinical stage distribution of patients according to the American Joint Committee on Cancer (4) was as follows: I, 3 (7%); II, 23 (53.5%); IIIA, 8 (18.6%); and IIIB, 9 (21%). Staging was determined in all patients by means of physical examination, chest radiograph, computerized tomography (CT) of the
Results
Median follow-up time for all patients was 42 months (range, 4–116 months). Because of some treatment interruptions, overall treatment time ranged from 30 to 129 days with a median of 51 days. The rate of treatment response, evaluated 30 days after the end of RT, was considered complete in 40 patients (93%) and partial in 3 (7%). No patients developed tumor progression during or up to 30 days after treatment. At the time of this analysis, 24 patients (55.8%) were alive with no evidence of
Discussion
Until the late 1970s, the conventional treatment for anal canal cancer was APR (8). This practice was challenged after the article by Nigro et al. was published in 1974 (3). They reported on 3 patients with squamous cell cancer of the anal canal who, after preoperative treatment with radiation plus concurrent chemotherapy, achieved a pathologic complete remission of the primary tumor at the time of surgery. The radiation dose used was 30 Gy, and chemotherapy was based on 5-FU and MMC. Since
Conclusions
This retrospective analysis suggests that the treatment strategy used was effective in terms of local control and sphincter preservation. However, incidence of acute toxicity and distant metastasis was relatively high. The clinical stage was the main prognostic factor for overall survival and colostomy-free survival. Local control was significantly higher in patients treated at primary tumor with a higher than 50 Gy radiation dose. Patients treated with more than 55 Gy did not have higher local
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2019, Seminars in Radiation OncologyCitation Excerpt :It should be emphasized that the study was limited to patients with cT2N0 disease, and studies with higher staged tumors do not have as positive of results. In a review of patients up to stage IIIB treated with INRT vs no INRT, Ferrigno et al reported increased inguinal failure for patients who did not receive elective INRT.44 Ortholan et al showed inguinal recurrence rates of 2% and 16% in elective INRT and non-INRT-treated patients, respectively.
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2013, International Journal of Radiation Oncology Biology PhysicsCitation Excerpt :The omission of prophylactic INRT in patients with T2N0 anal tumors remains controversial. Although different patient- and treatment-related factors may limit the comparability between series, the overall reported rate of inguinal relapse in studies including early-stage tumors remains relatively low, ranging between 0 and 8.6%, with isolated groin recurrences occurring in less than 5% of the cases (Table 4) (1,6,11-17). An exception is the high rate of inguinal recurrence (22.5%) observed by Matthews et al in a series of 40 patients with node-negative tumors ≤4 cm treated without INRT in a phase 2 study (13).
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2012, International Journal of Radiation Oncology Biology PhysicsCitation Excerpt :On the other hand, Ferrigno et al. reported a retrospective series of 43 patients. Of the 34 patients who did not received PII, 5 patients (15%) presented inguinal recurrence and the authors recommend systematic prophylactic inguinal irradiation (26). We reported here a 5-year rate of inguinal recurrence of 30% for T3-4 tumor, suggesting that, in these patients, prophylactic inguinal irradiation could improve groin control.