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Biomedical subjects

S H Quan

Publications and source records attributed to S H Quan.

At least 37 records · Page 2Linked to original sources
PubMed1985

Epidermoid cancer of the anal margin. Pathologic features, treatment, and clinical results.

Epidermoid cancer of the anal margin should be distinguished from that in the canal because of its different clinical and pathologic characteristics, the suitability of local excision for its treatment, and its better overall prognosis. In addition, margin cancer rarely metastasises to visceral sites. Forty-eight patients with epidermoid cancer of the anal margin were reviewed. Two refused treatment, 4 had palliative therapy for advanced, inoperable disease, 31 had local excision, and 11 were treated by abdominoperineal resection. Local excision provided satisfactory results with a corrected 5 year survival of 88 percent, although locoregional recurrence developed in 46 percent of these patients during follow-up. A second local excision or inguinal lymphadenectomy provided good results in the patients with recurrence. Abdominoperineal resection did not provide better overall survival figures.

Adult↗
PubMed1985

Treatment of epidermoid carcinoma of the anal canal.

Epidermoid carcinoma of the anal canal should be differentiated from that of the anal margin because of the different clinical presentations, pathologic characteristics, treatments and prognosis. The traditional treatment for carcinoma of the canal, abdominoperineal resection, produced a 55 per cent absolute five year survival rate but at the expense of permanent colostomy. Initial treatment with 5-fluorouracil and mitomycin C combined with external beam radiation therapy reduced the size of the tumor in 72 per cent of the patients and, with subsequent local excision or abdominoperineal resection, resulted in a 78 per cent survival rate in five years. The long term results from combined treatment are better than abdominoperineal resection alone with preservation of anal function in 45 per cent of the patients.

Adult↗
PubMed1984

Patterns of pelvic recurrence following definitive resections of rectal cancer.

Patterns of local and distant recurrences following resections for rectal cancer provide clinical perspective for multidisciplinary prevention and follow-up programs. From 1968 to 1976 at Memorial Hospital, 412 patients with potentially curable rectal cancer were treated by anterior (AR) or abdominoperineal (APR) resections. First sites of recurrences were categorized as pelvis, liver, distant viscera, and intraabdominal/retroperitoneal sites. Pelvic recurrences were further evaluated according to the location of the tumor, type of resection, and stage of disease. Among the 412 cases, 182 (44.2%) patients developed recurrence, of which 105 (57.6%) were pelvic. Pelvic recurrence was the predominating site either alone (55 of 103) or with concomitant extra-pelvic sites (50/79). In instances of single-site first recurrence, pelvic failure was recognized earliest at 19.1 months, which was significantly earlier than single-distant visceral sites at 34.9 months. Pelvic recurrence was selectively related to various categories of the Dukes and modified Dukes staging systems. Dukes stage significantly predicted pelvic recurrence rates for Dukes A verus B. Astler-Coller stages of B2 and C1 were associated with significantly lower rates of pelvic recurrence (29.7% and 22.1%, respectively) than C2 cancers. The incidence of pelvic recurrence was significantly increased for low and mid rectal cancers as compared with cancers at or above 12 cm. The type of resection utilized (APR versus AR) was associated with no difference in the rate of pelvic recurrence, except for the few patients in whom AR was performed for low rectal Dukes C cancers. Patients with pelvic recurrence had an ultimate disease-free survival of only 3.8% as compared with patients with no pelvic recurrence of whom 77% remained alive without disease or went on to die of other causes. The timing and predominance of pelvic failure in rectal cancer with its own treatment-related morbidity and overall dismal survival outcome justifies organized multidisciplinary efforts to prevent such failure and prospective trials of comprehensive follow-up programs to evaluate improved cure rates or palliation.

Female↗
PubMed1983

Preoperative chemotherapy and radiation therapy in the management of anal epidermoid carcinoma.

Management of epidermoid carcinoma of the anus has been primarily surgical in the past. Since it is a relatively rare entity, meaningful survival statistics are difficult to obtain. Five-year survival rates fall between 35 and 68% in patients treated with surgery and/or radiotherapy. Based on preliminary studies indicating promising results with the use of mitomycin C and 5-fluorouracil (5-FU) chemotherapy combined preoperatively with radiation therapy, these authors initiated a protocol in 1973 utilizing this multimodality approach. The preoperative treatment consisted of mitomycin C 15 mg/m2 IV bolus on day 1 and 5-FU 750 mg/m2/24 hours continuous infusion for five days. Radiation followed chemotherapy and consisted of 3000 rad given at 200 rad per day for 15 fractions. Of 37 patients entered on the protocol, 30 had primary disease and seven had been previously treated and had local recurrences. Median follow-up has been 28 months (range, 5-74 months). Of 31 patients with measurable lesions, 29 (94%) had major clinical responses (CR + PR) to the combined chemotherapy and radiation. Pathologic responses were also impressive with 53% (17/32) showing no evidence of residual tumor in the subsequently resected surgical specimen. Of the 37 patients treated, seven (19%) have had recurrences. The recurrence rate was 4/17 (24%) for those who had local excision following complete response to therapy as opposed to 3/18 (17%) for those treated by abdominoperineal resection. Thus it appears that the combination of preoperative mitomycin C and 5-FU with radiotherapy is effective at least in significantly downstaging this uncommon malignancy. Its ultimate effect on recurrence rate and overall patient survival awaits longer follow-up.

Adult↗
PubMed1983

Myosarcomas of the small and large intestine: a clinicopathologic study.

A retrospective study was made of 38 myosarcomas of the small and large intestines (34 leiomyosarcomas and 4 malignant leiomyoblastomas). Endoenteric, small, and noninvasive tumors were successfully treated by simple wedge excision, cautery snare removal, or segmental bowel resection with a high 5-yr cure rate of 86% (12/14). Exo-enteric tumors often invaded adjacent structures or perforated into the peritoneal cavity. Extensive resection procedures, including pancreaticoduodenectomy, abdominoperineal resection, and pelvic exenteration salvaged only 13% (2/16) of these patients. Three clinicopathologic factors adversely affected prognosis: i) tumor size greater than 5 cm in diameter, ii) extra-intestinal invasion or free perforation, and iii) high histopathologic grade of malignancy. The presence of none, one, two, or three of these adverse factors gave decreasing 5-yr survival rates of 100, 44, 31, and 0%, respectively. These observations suggest use of a multimodal treatment program that may minimize treatment failure from local as well as distant disease.

Adolescent↗
PubMed1981

Anorectal melanoma.

Primary malignant melanoma of the anorectum is a rare and virulent malignancy associated with an extremely poor prognosis in spite of aggressive initial therapy. Fifty-one patients with this disease were treated at Memorial Sloan-Kettering Cancer Center during the last 50 years and only six (12%) survived five years. This report views in detail 36 of the patients treated since 1950. In this group there was a female predominance (21 females, 15 males), and median age was in the 6th decade (range 27-75). Common presenting symptoms were pain, bleeding, mass or "hemorrhoids" of 1-12 months duration. In two-thirds, of the cases, a radical surgical approach was attempted. Other therapy included local excision alone or combined with groin dissection, local excision followed by delayed rectal resection and local tumor destruction by cryosurgery or fulguration. Mean survival was 21.5 months. Three patients had palliative treatment only with radiation therapy. Histopathologic study of 30 lesions showed that two-thirds were bulky or polypoid lesions and two-thirds showed junctional changes. The virulent prognosis of primary anorectal melanoma appears directly related to tumor size and thickness. Although all four of the five-year survivors had radical surgery, the three whose tumors could be measured had superficial lesions. In general, curative efforts by radical surgery were no more effective than local treatment by excision or cryosurgery. One patient, however, did have a thin lesion but also had nodal metastases and survived over five years after radical surgery. Although these data suggest that radical resection may cure patients with lesions thinner than 3 mm, it does not exclude the possibility that local excision might also be curative. For larger lesions that have not been cured by radical surgery, more conservative local approaches by excision or cryotherapy might be the optimum way of achieving local palliation.

Adult↗
PubMed1981

Malignant retrorectal tumors: 28 years' experience at Memorial Sloan-Kettering Cancer Center.

From 1949 to 1977, 39 patients with localized malignant retrorectal tumors were treated at Memorial Sloan-Kettering Cancer Center. Chordomas were the most frequent histologic type (38 per cent of patients) followed by neurogenic tumors (15 per cent) chondrosarcomas, hemangiopericytomas, and embryonal adenocarcinomas (8 per cent each). Treatment consisted of surgical excision in 28 patients (18 of whom received adjuvant radiotherapy and/or chemotherapy). Ten patients were treated nonsurgically, receiving radiation and/or chemotherapy alone. Large tumors were most successfully managed by a combined surgical approach consisting of exploratory celiotomy, rectal mobilization, and bilateral hypogastric artery (with middle sacral artery and vein) ligation, followed by transsacral tumor excision with incontinuity sacrectomy. For all treated patients, survival at 5, 10, 15 and 20 years was 69 per cent, 50 per cent, 37 per cent and 20 per cent, respectively. Long-term disease-free survival (17 to 25 years post treatment) was noted in six patients. [Key words: Tumor(s), retrorectal, malignant; Tumor(s), treatment].

Adolescent↗
PubMed1980

The significance of the signet-cell variety of adenocarcinoma of the rectum.

Seventeen cases of signet-cell mucinous adenocarcinoma of the rectosigmoid and rectum, seen over a 25-year period at Memorial Sloan-Kettering Hospital, were reviewed. We conclude, in agreement with previous authors, that it is an infrequent lesion that is usually discovered at an advanced stage. However, with early radical surgical intervention the prognosis can be favorable.

Adenocarcinoma, Mucinous↗
PubMed1979

Gardner's syndrome complicated by mesenteric desmoid tumors.

Mesenteric desmoid tumors present difficult management problems among patients with Gardner's syndrome. Appearance of the problem is associated with prior abdominal surgery and with pregnancy. In the authors' experience, radical surgery alone has failed to control the disease and they recommend that it should be avoided when possible. Bypass procedures, interstitial implantation of radioactive materials, and chemotherapy represent alternatives which require further evaluation.

Adult↗