Malignant epithelial tumors of the anal canal

Annals of Colorectal Research, 2013

Background: Malignant neoplasms of the anal canal are rare accounting for approximately 4% of all colorectal malignancies. Objectives: The present study aimed to report the clinicopathological characteristics and treatment outcomes of 41 cases with malignant neoplasms of the anal canal. Patients and Methods: Between 1999 and 2012, 41 consecutive patients were diagnosed with primary malignant neoplasm of the anal canal which were treated and followed up at Namazi hospital. Only primary malignant tumors arising from the anal canal were included. Patients with secondary anal canal involvement from rectal or perianal skin cancers and metastatic tumors were excluded. Results: There were 22 women and 19 men, age ranging from 33 to 83 years, with a median age of 57 years at diagnosis. Sixteen patients (39%) had localized disease, 21 (51%) had regional disease, and 4 (10%) had metastatic disease at diagnosis. Squamous cell carcinoma (61%) was the most frequent histologic subtype, followed by adenocarcinoma (27%), malignant melanoma (10%), and gastrointestinal stromal tumor (2%). After a median follow-up of 51 (11-169) months for surviving patients, 22 patients were alive and without disease, three were alive with disease, and 19 patients died due to the disease. Histological subtype (P = 001), and stage of disease (P = 0.002) were prognostic factors for overall survival. The 5-year local control, disease-free, and overall survival rates for all patients were 63.9%, 53%, and 59.4% respectively. Conclusions: This study indicated that squamous cell carcinoma, adenocarcinoma, and malignant melanoma are the most frequent malignant neoplasms in the anal canal. Histological subtype and disease stage are the most important prognostic factors for overall survival in this region.

Malignant tumours of the anal canal are rare and diverse group of tumours of gastrointestinal tract and comprises of 2.5 percent of all digestive system malignancy in United States. Although incidence rates are still low, there has been a significant increase in squamous cell carcinoma over the last 50 years. HIV infected homosexual men appear particularly at risk. HPV DNA is detectable in most anal squamous cell carcinomas. Despite its short length, the anal canal produces a variety of tumour type’s reflecting its complex anatomic and histological structure. Squamous, glandular, transitional, and melanocytic components occur at this site, either alone, or in combination. Due to the paucity of this malignancy it has been difficult to establish generally accepted guidelines for treatment. While for some neoplasms, the treatment of choice is clear-cut, for others it is still controversial. This review article makes an attempt to clarify current clinical, pathological and therapeutic options for anal canal tumors in the light of recent information.

Diseases of The Colon & Rectum, 1989

of the anal canal: results of treatment by combined chemotherapy and radiation therapy. Dis Colon Rectum 1989;32:773-777.

Diseases of the Colon & Rectum, 1986

From 1968 to 1982, 195 patients with invasive cancer of the anal canal were treated (average age, 67 + 11 years; range, 38 to 85 years; sex ratio [women/men]: 5/1). Histology revealed: cloacogenic cancer, 20 cases; squamous cancer, poorly differentiated, 30; moderately differentiated, 68; well differentiated, 77. The initial size of the cloacogenic cancers was smaller than the squamous cancers. Invasion less than half the circumference of the canal was 90 and 74 percent, respectively. No patients with cloacogenic cancer presented with positive inguinal nodes; however, there were 22 unilateral and five bilateral positive nodes in the squamous cancers. All 195 patients received radiotherapy as the first treatment. There were no differences among the patients operated on with respect to sterilized operative specimens, postradiotherapy sequelae, perineal recurrences, and/or visceral metastases in the cloacogenic and squamous cancers. Five-year survival was better in cloacogenic (62 percent) than in squamous cancers (56 percent); this difference was not significant, and was related to the initial size of the tumor. The number of patients with no evidence of disease and good anal function was significantly related to the initial size of the tumor, and was independent of the histoiogic findings.

Oncology Reviews, 2009

There are around 5,000 new cases of anal canal cancer each year in the United States. It is of particular risk in HIV-positive populations. Many cases are related to persistent infection with human papillomavirus (HPV). The treatment of anal cancer has progressed from abdominoperineal resection mandating permanent colostomy in the 1940s through the 1970s to modern chemoradiation with sphincter preservation

2018

Malignant tumors of the anal canal are considered to be a rare neoplasm represents 0.43% of all malignancies and 2% of the digestive tract malignant tumors [1,2]. Overall, the most common cancer of the anal canal is squamous cell carcinoma (85%), followed by adenocarcinomas (10%). The other rare types such as melanoma, basaloid carcinoma and lymphoma represent less than 5% of all diagnosed tumors of the anal canal [2].

International Journal of Radiation Oncology*Biology*Physics, 1989

From 1972 to 1985, 260 cases of anal canal epidermoid carcinoma were irradiated. Eighteen cases treated for palliation were excluded from the study; 242 (93%) were treated with curative intent. The sex ratio was l/5.5; mean age was 66 years. Histology: 60.3% were well differentiated epidermoid carcinoma; 31.0% moderately differentiated and 8.7%, cloacogenic cases. Staging: Tl: 11.5% T2: 16.1%; T3a: 17%; T3b: 33.5%; and T4: 21.9%. Abnormal inguinal nodes were present in 15.3% of cases. Crude overall survival (Kaplan-Meier) for the 242 cases is 86.4% at 1 year, 63.9% at 3 years, 51.2% at 5 years, and 30.8% at 10 years. Radiation therapy was the sole treatment for 193 cases. No chemotherapy was given. Patients were irradiated by external beam. They received a first course of X rays (mostly 18 MV, some 6 MV) 40 to 45 Gy (box technique) over 4 to 5 weeks in the pelvis. Age and size of tumor were considered when deciding on the target volume. After a rest period of 4 to 6 weeks, a second course of 15 to 20 Gy in 2 weeks was given through a perineal field by electron-beam of suitable energy. The mean total dose was 60.56 Gy and median was 62.5 Gy; the mean overall treatment duration was 85.3 days (median 82 days) and the mean Time Dose Factor including decay factor was 98.96. In this group, 5-year determinate survival was: Tl-T2, 84.5%; T34 74.8%; T3b, 64.9%; T4, 58.9%. In 147/193 patients (76.2%) local control was achieved. The overall anal conservation rate was 62.6%. In 106 cases (55%), the anus had maintained normal function. The 5-year survival rate by N was 73.3% in the absence of inguinal nodes (169 cases) and 36.1% if such nodes were present. There was no significant difference in survival rate according to histological type. In the second group, receiving radiation therapy plus surgery, 33/49 cases (T3b-T4) were irradiated before surgery (median dose 40.5 Gy). Post operative radiation therapy was administered in 16 cases (T3b-T4) (median dose 49.6 Gy). The 5year determinate survival is 53.2% for T3b and 79% for T4. According to the log-rank test, there was no significant difference between survival with radiation therapy alone and radiation therapy plus surgery. Multivariate analysis of the whole group indicated that T stage is the only predictive variable. Non-predictive variables are: nodal status, histology, age, total dose, overall treatment time, and irradiation technique. There is no significant relationship between the complication rate (severe complications: 9.3%) and the aforementioned variables. Because of the homogeneity of the irradiation doses, no significant relationship was found between dose and local control rate or complication rate.

International Journal of Surgical Oncology, 2020

Background. Anal canal adenocarcinoma (AA) is an uncommon tumor of the gastrointestinal tract. We seek to provide a detailed description of the incidence, demographics, and outcome of this rare tumor in the United States. Methods. The data on anal canal adenocarcinoma from SEER Program, between 1973–2015, were extracted. We analyzed the incidence rates by demographics and tumor characteristics, followed by analysis of its impact on survival. Results. The incidence of AA increased initially by 4.03% yearly from 1973 to 1985 but had a modest decline of 0.32% annually thereafter. The mean age for diagnosis of AA was 68.12 ± 14.02 years. Males outnumbered females by 54.8 to 45.2%. Tumors were mostly localized on presentation (44.4%) and moderately differentiated (41.1%). Age generally correlated with poor overall cancer survival. However, young patients (age <40 years) also showed poor long-term survival. Patients with localized disease and well-differentiated tumors showed better su...

Surgery Today, 2006

A 70-year-old man with a history of colon polyps was found to have a semipedunculated polyp in the anal canal. The patient was asymptomatic. The lesion was 14 mm in diameter and located 5 mm from the dentate line. Histological examination of biopsy specimens revealed well-differentiated adenocarcinoma of the anal canal. During transanal local excision of the tumor, an abnormality of the perianal skin was recognized. Although intraoperative frozen section of the perianal skin did not show malignancy, permanent sections of the perineal skin revealed Paget's cells in the epidermis. Pathological examination of the anal canal carcinoma revealed submucosally invasive well-differentiated adenocarcinoma with a positive distal surgical margin. Thus, we performed additional wide local excision of the perianal skin including the distal margin of the previous local excision. Pathological examination revealed continuance within the epidermis between the anal canal adenocarcinoma and Paget's cells in the perianal skin lesion. Scattered Paget's cells also formed some glandular structures. Thus, we concluded that the perianal skin lesion was Pagetoid spread of anal canal adenocarcinoma. This report shows that the perianal skin should be examined carefully in patients with anal canal carcinoma.

International Journal of Radiation Oncology Biology Physics, 2003

Primary adenocarcinoma of the anus is a rare tumor. The current standard treatment consists of abdominoperineal resection (APR). The aim of this Rare Cancer Network study was to evaluate the prognostic factors and outcome after the three most commonly used treatment approaches.This multicenter study collected data from 82 patients: 15 with T1 (18%), 34 with T2 (42%), 22 with T3 (27%), and 11 with T4 (13%) tumors according to the TNM classification (International Union Against Cancer, 1997). Patients were separated into, and analyzed according to, three treatment categories: radiotherapy/surgery (RT/S group, n = 45), combined radiochemotherapy (RT/CHT group, n = 31), and APR alone (APR group, n = 6). The main patient characteristics were evenly distributed among the three groups.The actuarial locoregional relapse rate at 5 years was 37%, 36%, and 20%, respectively, in the RT/S, RT/CHT, and APR groups (RT/S vs. RT/CHT, p = 0.93; RT/CH vs. APR, p = 0.78). The 3-, 5-, and 10-year overall survival rate was 47%, 29%, and 23% in the RT/S group, 75%, 58%, and 39% in the RT/CHT group, and 42%, 21%, and 21% in the APR group (RT/CHT vs. RT/S, p = 0.027), respectively. The 5- and 10-year disease-free survival rate was 25% and 18% in the RT/S group, 54% and 20% in the RT/CHT group, and 22% and 22% in the APR group (RT/CHT vs. RT/S, p = 0.038), respectively. Multivariate analysis revealed four independent prognostic factors for survival: T stage, N stage, histologic grade, and treatment modality.Primary adenocarcinoma of the anal canal requires rigorous management. Multivariate analysis showed that T and N stage, histologic grade, and treatment modality are independent prognostic factors for survival. We observed better survival rates after combined RT/CHT. We also recommend using APR only for salvage treatment.