Squamous Cell Carcinoma Of Rectum Research Articles

Comparison of outcomes between rectal squamous cell carcinoma and adenocarcinoma.

Large, population‐based analyses of rectal squamous cell carcinoma (SCC) have not been previously conducted. We assessed patterns of care, prognostic factors, and outcomes of rectal SCC and adenocarcinoma (AC) in population‐based cohorts. Surveillance, Epidemiology, and End Results (SEER) registry searches were performed (1998–2011), producing 42,308 nonmetastatic rectal cancer patients (999 SCC and 41,309 AC). Patient, tumor, and treatment characteristics were compared. Based on risk factors, SCC/AC groups were subdivided into low‐, intermediate‐, and high‐risk groups. Overall survival (OS) was compared between histological and risk groups using Kaplan–Meier method and log‐rank test. Multivariate logistic regression models evaluated prognostic factors for 5‐year survival. Cox regression modeling was performed on propensity‐matched data. Rectal SCC, more common in females and associated with larger tumors of higher grade, was more often treated with radiotherapy (RT) than surgery. Surgery was associated with higher OS in AC but not SCC, and RT had proportionally greater benefits in SCC. These effects of RT and surgery were retained when stratified into risk groups (particularly high/intermediate‐risk). Favorable prognostic factors for survival included younger age, non‐black race, SCC histology, size ≤3.9 cm, localized stage, lower grade, surgery, and RT. For SCC, race, tumor grade, and surgery were not prognostic factors for survival. Cox regression modeling of propensity‐matched data showed that AC histology increased risk of death versus SCC. In the largest analysis of rectal SCC to date, and in the notable absence (and unlikelihood) of prospective data, nonsurgical and RT‐based treatment is recommended.

Prise en charge du carcinome épidermoïde du rectum : expérience de deux centres universitaires français, revue de la littérature et recommandations

After publishing a retrospective series of 23 patients treated for a rectal squamous cell carcinoma with exclusive curative and conservative intent chemoradiation, we aim to propose a review of the literature about this rare tumour. We identified 11 retrospective studies, on 106 patients, treated between 2007 and 2016. Treatment of rectal squamous cell carcinoma should be similar to anal carcinoma, based on exclusive chemoradiation, displaying a 5-year overall survival rate over 80%, while it was 32% in surgical series. Baseline explorations should be similar as for anal carcinoma, with an interest in PET-CT at diagnosis and monitoring, after a delay over 6 weeks after chemoradiation. Intensity-modulated radiotherapy is legitimate, to a prophylactic dose between 36 and 45Gy, and over 54Gy to the tumour. Concomitant chemotherapy should combine an antimetabolite (5-fluorouracil or capecitabine) and mitomycin C, or cisplatin. This treatment seems well tolerated, associated with grade 2 or above toxicity below 30%. Follow-up should be established on anal squamous cell carcinoma schedule, with endoscopic ultrasonography and PET-CT. Rectal squamous cell carcinoma is a rare tumour; it management should be based on anal curative and conservative intent chemoradiation.

Primary Rectal Squamous Cell Carcinoma Presenting as a Symptomatic Pre-sacral Mass: A Case Report

Primary Rectal Squamous Cell Carcinoma Presenting as a Symptomatic Pre-sacral Mass: A Case Report

Chemoradiation in rectal squamous cell carcinoma: Bi-institutional case series

Background and purposePrimary rectal squamous cell carcinoma (SCC) is an uncommon disease. Early reports stated that surgery is the most effective treatment. However, recent publications suggest conservative strategy with chemoradiation provides satisfactory results. Patients and methodsWe have retrospectively studied the medical charts of 23 patients treated for a rectal SCC in two teaching hospitals in France between 1992 and 2013. Twenty-one patients received an exclusive chemoradiotherapy (CRT) and two a pre-operative CRT followed by a planned surgery. Patients received pelvic irradiation with a dose ranging from 36–45 Gy followed by a boost of 15–23 Gy. Twenty-two patients received a concurrent chemotherapy. ResultsAfter CRT, the rate of clinical complete response was 83%. With a median follow-up of 85 months, 5-year overall survival rate was 86%. Five patients presented with a relapse. The 5-year disease-free survival rate was 81%. The 5-year colostomy-free survival rate was 65%. Three patients (13%) presented with grade III–IV late rectal toxicity. ConclusionsAlthough retrospective, this is the largest cohort of patients treated with CRT for a rectal SCC. Exclusive CRT could result in high local control rate and prolonged survival in rectal SCC patients with a high rate of organ preservation.

Systemic therapy for advanced anorectal squamous cell carcinomas: A single institutional experience.

728 Background: Anorectal squamous cell carcinomas (SCCs) are rare in the United States with < 10,000 cases annually. Uncommonly, patients present with stage IV disease or recurrence after definitive therapy. Limited options exist for these patients. We queried Roswell Park Cancer Institute (RPCI) patient records to determine systemic treatments utilized and outcomes for these patients. Methods: Patients with anal or rectal SCC between 1/1/99 and 7/1/2014 were identified via the cancer registry. 65 patients were flagged for review. From manual review, 31 patients received treatment at RPCI and were deemed evaluable. Demographic data, histology, staging, treatment history, time receiving any specific therapy and response assessment were abstracted from the records. Results: Of the 31 patients, 45% were male, 55% female. Primary tumors were anorectal (84%) or rectal (16%) in origin. 5(16%) presented with rectal SCC. Sites of metastatic disease were most commonly identified as lymph nodes (48%), liver (35) or lung (16%). At the time of analysis 5 (16%) were alive, with 3 (10%) disease free. Median overall survival (OS) was 44.1 months (95% CI, 28.9 - 62.6). The most commonly utilized chemotherapy regimens were 5-fu/cisplatin (n = 22 patients) and taxol (n = 10). Mean time on therapy was 4 months for 5-fu/platinum doublets (n = 24), 4 months for taxanes/platinum combinations (n = 6), 3.4 months for anti-EGFR containing regimens (n = 7) and 2.43 months for taxane monotherapy (n = 10). The most common reasons for discontinuation of therapy were progressive disease (47%) or patient choice (15%). Conclusions: New therapies are desperately needed for advanced anorectal SCCs. At present, 5-FU/cisplatin is the best endorsed and most frequently utilized regimen. Consistent with other reports, platinum doublets and anti-EGFR targeted therapies appear to confer significant benefits, within the realm of 5-fu/cisplatin, with single agent taxanes appearing to have lesser activity. Small absolute patient numbers and lack of reliable response measurements preclude firm conclusions. Future clinical trials to evaluate systemic therapies in advanced anorectal SCCs, including anti-EGFR regimens, are warranted.

Rectal squamous cell carcinoma in immunosuppressed populations: is this a distinct entity from anal cancer?

Squamous cell carcinoma (SCC) of the rectum is rare, but as with anal cancer, risk may be increased among immunosuppressed individuals. We assessed risk of rectal SCC in HIV-infected people. Population-based registry. We utilized the HIV/AIDS Cancer Match, a linkage of US HIV and cancer registries (1991-2010), to ascertain cases of anal SCC, rectal SCC, rectal non-SCC, and colon non-SCC. We compared risk in HIV-infected persons with the general population using standardized incidence ratios (SIRs) and evaluated risk factors using Poisson regression. We reviewed cancer registry case notes to confirm site and histology for a subset of cases. HIV-infected persons had an excess risk of rectal SCC compared with the general population (SIR = 28.9; 95% CI 23.2-35.6), similar to the increase for anal SCC (SIR = 37.3). Excess rectal SCC risk was most pronounced among HIV-infected MSM (SIR = 61.2). Risk was not elevated for rectal non-SCC (SIR = 0.88) or colon non-SCC (SIR = 0.63). Individuals diagnosed with AIDS had higher rectal SCC rates than those with HIV-only (incidence rate ratio = 1.92; 95% CI 1.08-3.42). Based on available information, one-third of rectal SCCs were determined to be misclassified anal cancer. HIV-infected individuals, especially with advanced immunosuppression, appear to have substantially elevated risk for rectal SCC. As for anal SCC, rectal SCC risk was highest in MSM, pointing to involvement of a sexually transmitted infection such as human papillomavirus. Site misclassification was present, and detailed information on tumour location is needed to prove that rectal SCC is a distinct entity.

Primary squamous cell carcinoma of the rectum: An update and implications for treatment.

To provide an update on the aetiology, pathogenesis, diagnosis, staging and management of rectal squamous cell carcinoma (SCC). A systematic review was conducted according to the preferred reporting items for Systematic Reviews and Meta-Analyses guidelines. A comprehensive search of Ovid MEDLINE was performed with the reference list of selected articles reviewed to ensure all relevant publications were captured. The search strategy was limited to the English language, spanning from 1946 to 2015. A qualitative analysis was undertaken examining patient demographics, clinical presentation, diagnosis, staging, treatment and outcome. The quantitaive analysis was limited to data extracted on treatment and outcomes including radiological, clinical and pathological complete response where available. The narrative and quantitative review were synthesised in concert. The search identified 487 articles in total with 79 included in the qualitative review. The quantitative analysis involved 63 articles, consisting of 43 case reports and 20 case series with a total of 142 individual cases. The underlying pathogenesis of rectal SCC while unclear, continues to be defined, with increasing evidence of a metaplasia-dysplasia-carcinoma sequence and a possible role for human papilloma virus in this progression. The presentation is similar to rectal adenocarcinoma, with a diagnosis confirmed by endoscopic biopsy. Many presumed rectal SCC's are in fact an extension of an anal SCC, and cytokeratin markers are a useful adjunct in this distinction. Staging is most accurately reflected by the tumour-node-metastasis classification for rectal adenocarcinoma. It involves examining locoregional disease by way of magnetic resonance imaging and/or endorectal ultrasound, with systemic spread excluded by way of computed tomography. Positron emission tomography is integral in the workup to exclude an external site of primary SCC with metastasis to the rectum. While the optimal treatment remains as yet undefined, recent studies have demonstrated a global shift away from surgery towards definitive chemoradiotherapy as primary treatment. Pooled overall survival was calculated to be 86% in patients managed with chemoradiation compared with 48% for those treated traditionally with surgery. Furthermore, local recurrence and metastatic rates were 25% vs 10% and 30% vs 13% for the chemoradiation vs conventional treatment cohorts. The changing paradigm in the treatment of rectal SCC holds great promise for improved outcomes in this rare disease.

Comparison of Survival Outcomes of Rectal Squamous Cell Carcinoma With Rectal Adenocarcinoma

745 Background: Rectal squamous cell carcinoma (RSCC) is a rare disease. It is unclear whether the prognosis or treatment outcomes differ from that of rectal adenocarcinoma (RAC). The objective of ...

Comparison of survival outcomes of rectal squamous cell carcinoma with rectal adenocarcinoma.

745 Background: Rectal squamous cell carcinoma (RSCC) is a rare disease. It is unclear whether the prognosis or treatment outcomes differ from that of rectal adenocarcinoma (RAC). The objective of this study is to compare the overall survival (OS), cancer specific survival (CSS) and prognostic factors of RSCC to those of rectal adenocarcinoma (RAC) using the Surveillance, Epidemiology, and End Results (SEER) registry. Methods: A total of 42,317 patients diagnosed with RSCC (999) and RAC (41,318) without distant metastasis between 1998 and 2011 were identified from the SEER database. Factors analyzed included histology (RSCC/RAC), age (≤56/>56), gender, race (white/nonwhite), tumor size (<5 cm/≥5 cm), grade (well-moderate/poor-undifferentiated), stage (local/regional), year of diagnosis (1998-2003/2004-2011), with or without surgery, and with or without radiotherapy (RT). OS and CSS were evaluated using the Kaplan-Meier method. Cox proportional hazards regression analysis was performed to examine the prognostic factors for survival. Results: The median follow up is 77 months (M). The entire group had 5 year OS and CSS of 62% and 77% with a median OS of 95 M but did not reach a median CSS. Compared to patients with RAC, patients with RSCC tend to be younger, female, diagnosed more recently, with less advanced stage but higher grade and larger tumor size. For patients with RSCC, 40% underwent surgery and 75% received RT. In contrast, for patients with RAC, 89% underwent surgery and 59% received RT. Patients with RSCC had a higher median OS than those with RAC (105 vs 94 M, Log-rank p <0.05). Cox proportional hazards analysis showed that patients with RAC had worse OS (hazard ratio [HR] 1.4) and CSS (HR 1.6) than patients with RSCC (p<0.05), after adjusting for all prognostic factors. Factors associated with improved OS and CSS in both RSCC and RAC included age ≤56, nonwhite, early stage, well-moderate differentiated, undergoing surgery and receiving RT. Gender is a prognostic factor for OS but not for CSS. Conclusions: Patients with rectal squamous cell carcinoma had a significantly superior OS and CSS than patient with rectal adenocarcinoma. Future studies should seek to explore the optimal management for these two distinct diseases.

Nonoperative management of squamous-cell carcinoma of the rectum.

Radiochemotherapy without surgical resection has become the treatment of choice for anal squamous-cell carcinoma. The optimal treatment for rectal squamous-cell carcinoma is not well established. The purpose of this work was to assess the efficacy of nonoperative strategies in the management of primary rectal squamous-cell carcinoma. We retrospectively reviewed data from all of the patients with documented rectal squamous-cell carcinoma who were treated with conservative strategies in a single institution. Concomitant radiochemotherapy was proposed to all except 1 patient. The remaining patient was treated by radiotherapy alone given his impaired functional status. All of the patients were treated with conformal or intensity-modulated radiation therapy. Surgical resection was reserved for persistent disease or relapse. This study was conducted in a single tertiary institution. After a mean follow-up of 56 months, 2 patients experienced relapse and no patients died. Eleven patients were included in the series. The clinical response to radiotherapy was complete for 7 patients. The remaining 4 patients underwent salvage surgery. The pathologic response was incomplete for 2 of the 4 patients. One recurrence occurred outside the field of radiotherapy and was successfully treated by radiotherapy. The second was a local recurrence, which occurred on a patient who was treated with radiotherapy alone. The number of patients included in this retrospective series was limited because of the rarity of the disease. Patients were treated with nonhomogeneous conservative strategies because of modification in the therapeutic strategy for anal squamous-cell carcinoma and of the adaptation of the treatment to patient comorbidities and functional status. This series demonstrates that good results can be obtained by using a rectum-conserving strategy. Close follow-up should be maintained, with the use of salvage surgery reserved only for persistent disease or relapse (see Video, Supplemental Digital Content 1, http://links.lww.com/DCR/A155).

Rectal Squamous Cell Carcinoma in a Patient with Familial Adenomatous Polyposis

Squamous cell carcinoma of the rectum is extremely rare, with an incidence between 0.25 and 1 case per 1,000 cases of colorectal carcinoma. In familial adenomatous polyposis (FAP), characterized by the progressive development of hundreds to thousands of adenomatous colonic polyps, unscreened patients and those who are not treated at an early stage of the disease have an extremely high risk of developing colorectal adenocarcinoma. A few reports of squamous cell carcinoma of the rectum have been published but none of the patients had FAP. Here, we report the case of a 17-year-old male with FAP who developed rectal squamous cell carcinoma. (Korean J Med 2015;88:335-339)

A Case of Rectal Squamous Cell Carcinoma Mistaken for Rectal Adenocarcinoma

<title>Abstract We report a case of anal squamous cell carcinoma extended to the rectal mucosa that was clinically mistaken for rectal adenocarcinoma and literature reviwed. Sigmoidoscopic finding showed spherical shaped elevated lesion with central ulceration, interpreted as rectal adenocarcinoma in the distal portion of rectum. Anal squamous cell carcinoma is very rare among gastrointestinal cancer. Pathological study of the biopsy specimen demonstrated squamous cell carcinoma and normal rectal glands. Sigmoidoscopic finding of the presented case showed the ulcerarive lesion contineuosly extended from anal verge upward to the rectum. We postulate that the presented case is primarilly originated from the anal squamous cell carcinoma extended proximally to the rectum. Immunohistochemical stain(p-63) of the biopsy specimens showed squamous cell carcinoma. This patient has been completely recovered after treartment of chemoradiation and trans-anal excision. We present a case of anal squamous cell carcinoma invading rectal mucosa clinically mistaken for rectal adenocarcinoma and literature reviewed.</p>

Squamous Cell Cancer of the Rectum: A Case Report

Introduction: Primary squamous cell carcinoma (SCC) of the colon and rectum are rare malignancies accounting for less than 0.025% of all colonic malignancies. Most reported cases were strongly associated with HIV positive state, immunosuppressive therapy, inflammatory bowel diseases (IBD), and other chronic disease states. Mucosal metaplasia is believed to be the leading cause of this form of carcinoma. We present a patient with squamous cell carcinoma of the lower rectum who underwent neoadjuvant chemoradiation therapy and planned for abdominoperineal resection. A 72-year-old female presented for bright red blood per rectum. The patient had 6-7 bloody bowel movements before her presentation. She was also complaining of a “naggy” abdominal pain. She was hemodynamically stable and her physical exam was unremarkable. A colonoscopy was performed, which revealed a large malignant-appearing mass in the lower rectum at about 1 cm from the anal verge measuring at least 5 cm in size. Also, 2 flat polyps were found. Polypectomy was done and biopsies were taken. Given the large malignant-appearing rectal mass, a flexible sigmoidoscopy with endoscopic ultrasound was performed that demonstrated a 6x5-cm ulcerated mass in the distal rectum, located 1 cm above the anal margin staged initially to be T3N0M0. The pathology reported moderately differentiated squamous cell carcinoma. An extensive work-up did not show any other lesions in the chest or in the abdomen. However, a PET scan highlighted multiple liver lesions, but the ultrasound-guided FNA of 1 of these lesions came back negative for malignancy. Based on the pathology report, and given the very distal location of the rectal mass, the plan was to start with a neoadjuvant chemoradiation therapy followed by an abdominoperineal resection. Squamous cell carcinoma of the rectum is an extremely rare histopathological entity. Many questions regarding its histogenesis and biological behaviour remain unanswered, but several hypotheses have been suggested, including human papilloma virus infection, chronic underlying inflammatory disease processes, or altered immune status. Gynecological cancer is an important differential diagnosis in females with involvement of the genital organs. Nowadays, surgery is the treatment method of choice, and adjuvant radiation and chemotherapy are recommended in advanced stages of the disease. With a greater awareness among surgeons and pathologists, more cases may become known, leading to a better understanding of this tumor’s behavior.

A Case of Rectal Squamous Cell Carcinoma with Metachronous Diffuse Large B Cell Lymphoma in an HIV-Infected Patient.

Diffuse large B cell lymphoma (DLBCL) is one of the most common acquired immune deficiency syndrome (AIDS)-defining malignancies among human immunodeficiency virus-infected patients, and rectal cancer has recently emerged as a prevalent non-AIDS-defining malignancy. We report a case of rectal squamous cell carcinoma that was metachronous with DLBCL in an HIV-infected patient who was receiving highly active antiretroviral therapy. The patient was diagnosed with DLBCL and showed complete remission after chemotherapy. Follow-up imaging showed increased uptake at the rectum, previously treated as lymphoma. Repeated biopsy was performed and squamous cell carcinoma of the rectum was reported. After concurrent chemoradiation therapy, curative resection was performed.

Squamous Cell Carcinoma of the Rectum: A Case Report of a Rare Disorder

Purpose: Primary squamous cell carcinoma (SCC) of the GI tract is a rare malignancy with a far lower incidence than primary adenosquamous cell carcinoma of the GI tract. Schmidtmann described the first case in 1919 by presenting a squamous cell carcinoma of the large intestine localized to the cecum. Of the locations described in literature, primary rectal SCC tumors were the most frequent, followed by the right colon. Primary squamous cell carcinoma of the rectum has an incidence 0.1 per 1000 colorectal carcinomas, with fewer than one hundred cases described in literature since 1919. The patient is a 50-year-old male with PMH significant for HIV off HAART and no history of AIDS defining illness, who presented to the ED with complaint left-sided pain, mid abdominal tenderness, and constipation with significant straining to use the bathroom and dark/bloody stools. He reported he had an external rectal condyloma removed four months prior to admission. The patient noted 10 pounds weight loss over last four months. The patient noticed significant constipation, thin stools and in the last month dark blood with bowel movements (never occurred prior), and has had increasing abdominal pain initially mid epigastric, 5/10 aching, but then progressed to right upper abdomen and then diffuse. He had his first occurrence of bright red blood with bowel movement, which prompted admission. The patient's vitals were stable, and on exam, his abdomen was significant for distention, tenderness to mid-epigastric region, hepatomegaly, external hemorrhoids, and guaiac-positive stool. Other systems were normal. Laboratory results were significant for hemoglobin of 7.3 g/dl, albumin of 2.8 g/dl, and corrected calcium of 13.8 mg/dl. Computed tomography (CT) revealed perirectal mass, diffuse lymphadenopathy, and multiple hepatic masses. Colonoscopy with approximately 4 cm non-obstructing firm and friable mass located at the junction of the anal canal and rectum. Rectal mass pathology consistent with invasive, poorly-differentiated squamous cell carcinoma with basaloid features. Due to advanced stages and aggressive nature of his cancer, the patient was started on palliative radiation with 45 Gy in 15 fractions to the anus and 30 Gy in 15 fractions to the liver. Prognosis has been reported very poor in this case.Figure

Early recurrence and progression of a rare rectal squamous cell carcinoma after initial response to primary chemoradiotherapy

Rectal squamous cell carcinomas represent an extremely rare malignancy which carries a significant morbidity and mortality. Diagnosis requires distinction from squamous cell carcinoma of the anus and colonic adenocarcinoma by endoscopy and histopathological examination of a biopsy. Due to the rarity of the pathology, available evidence is limited and optimum management has yet to be elucidated. Older reports favored radical surgical management, but recent reports in the literature recommend judicious use of primary chemoradiotherapy. We herein report the diagnosis and management of a male patient with an aggressive, locally advanced rectal squamous cell carcinoma treated with good results with primary chemoradiotherapy. Six months after completion of therapy, however, extensive recurrence and metastases were diagnosed. This case highlights the need for stringent clinical and radiological follow-up.

Squamous cell carcinoma of the rectum: a single institution experience

Squamous cell carcinoma (SCC) of the rectum is a rare disorder. There is currently no effective method as to how best treat patients with this condition. The purpose of this study was to review a single tertiary institution's experience. A retrospective chart review was conducted of all patients who presented with documented SCC of the rectum over a 10-year period (2000-2010). During the study period, all patients were offered chemoradiation as an initial treatment modality [a fluorouracil (5-FU)-based regimen in conjunction with mitomycin or cisplatin]. Six patients presented with primary rectal SCC. Mean patient age was 60years. The majority of patients were female (83%). The most common presenting symptom was rectal bleeding (67%). The mean distance from the inferior tumor margin to the anal verge was 6cm. Two patients (33%) presented with stage II disease, and 4 (67%) were stage III. Five patients (83%) received chemoradiation therapy initially, and 1 patient underwent abdominoperineal resection after refusing chemoradiation. Two additional patients (33%) underwent salvage surgery. During a mean follow-up of 44months, 4 patients (66%) were alive without evidence of disease. Based on the results of this cases series, chemoradiation as an initial primary therapy appears to be beneficial for patients with primary SCC of the rectum. A 5-FU chemotherapy-based regimen in conjunction with fractionated radiotherapy appears to be effective for local control of the disease.

Primary Rectal Squamous Cell Carcinoma

Primary Rectal Squamous Cell Carcinoma

A Rare Case of Rectal Squamous Cell Carcinoma in a Male Ulcerative Colitis Patient Treated with Mercaptopurine

A Rare Case of Rectal Squamous Cell Carcinoma in a Male Ulcerative Colitis Patient Treated with Mercaptopurine

Rectal squamous cell carcinoma treated with chemoradiotherapy: report of six cases

Squamous cell carcinoma (SCC) of the colon and rectum is a rare pathologic entity. From May 2006 to August 2008 six consecutive patients with SCC of the rectum were treated at our institution. A retrospective analysis of these cases was performed in order to evaluate the role of chemoradiotherapy as an alternative to surgery. All tumors were locally advanced and the clinical stage was T3N0M0 in three cases, T3N1M0, T4N1M0 and T3N2M1 in the other three cases. All patients received primary chemoradiation reserving surgery for unresponsive or recurrent tumors except in one of complete responders. Radiation treatment was given to standard pelvic volume up to 50.4 Gy in 28 fractions, with a boost to the primary tumor up to 59.4 Gy in two patients. A complete clinical response with a negative endoscopic biopsy was achieved in four patients and a partial response in two. Surgery as a part of the primary treatment was performed in the non-metastatic patient with partial response and in the first patient with complete response. At a median follow-up of 39 months (range, 24-41) from the end of chemoradiotherapy, five out of six patients remain alive and free of recurrence, three of them without having undergone surgery. Our data, though from a small series, give support to the hypothesis that concomitant chemoradiation may be considered a safe and effective therapeutic approach for patients with rectal SCC.