Colorectal carcinoma in childhood and adolescence: a clinicopathologic review.

PURPOSE: Pediatric colorectal carcinoma (CRC) is rare, but the available data suggest that it is more likely than adult CRC to be advanced at presentation and to have a poor outcome. We sought to better characterize pediatric CRC. PATIENTS AND METHODS: We reviewed the clinical and pathologic features, prognostic factors, and outcome of CRC in 77 children and adolescents (ages 7 to 19 years) referred to St Jude Children's Research Hospital between 1964 and 2003. RESULTS: At presentation, 76 patients had one or more signs or symptoms of CRC (abdominal pain, altered bowel habits, weight loss, anemia). Tumors were evenly distributed between the right and left colon; 62% were mucinous adenocarcinoma. At presentation, 86% of patients had advanced-stage disease; more than half had distant metastases. Overall outcome was poor. Advanced stage and mucinous histology were significant predictors of adverse outcome. Stage-specific survival at 10 years was 67% +/- 27% (stage 1), 38% +/- 15% (stage 2), 28% +/- 11% (stage III), and 7% +/- 4% (stage 4). Although no patient had a diagnosis of polyposis syndrome before diagnosis of CRC, 17 (22%) had colon polyps and eight (including two who previously underwent pelvic radiotherapy) had multiple polyps. CONCLUSION: Initial signs and symptoms of CRC are similar in pediatric and adult patients. The strikingly higher frequency of mucinous histology suggests that the biology of CRC differs in pediatric and adult patients and may contribute to poor outcomes. Children should be included in prospective clinical trials for CRC.

Real-time polymerase chain reaction as an aid for the detection of SYT-SSX1 and SYT-SSX2 transcripts in fresh and archival pediatric synovial sarcoma specimens: report of 25 cases from St. Jude Children's Research Hospital.

Synovial sarcoma is the most common nonrhabdomyosarcomatous soft tissue sarcoma in children and adolescents and is characterized by a reciprocal t(X;18)(p11;q11) which results in the fusion of the SYT gene on chromosome 18q11 to either of two closely related genes, SSX1 (Xp11.23) or SSX2 (Xp11.21). Detection of this translocation or its resultant gene fusion by molecular methods is helpful in the pathologic diagnosis of synovial sarcoma, especially in poorly differentiated tumors. This study was designed to evaluate the utility of a real-time reverse transcriptase-polymerase chain reaction (RT-PCR) assay to detect and distinguish SYT-SSX1 and SYT-SSX2 fusions in fresh and archival specimens of synovial sarcoma in pediatric patients seen at St. Jude Children's Research Hospital. In addition, the clinicopathologic features of the tumors with SYT-SSX1 vs. SYT-SSX2 fusions were compared. The 25 patients studied had a median age of 13 years 9 months (range 5 to 19 years). Estimates of survival and event-free survival at 5 years were 78.7 +/- 10.5% and 56.2 +/- 13.2%, respectively. Seventeen (68%) tumors were monophasic, eight (32%) were biphasic. Seven tumors contained poorly differentiated areas. Positive results for either SYT-SSX1 or SYT-SSX2 were obtained in 21/25 (84%) cases. Three cases did not have a detectable gene fusion and one had no amplifiable RNA. SYT-SSX1 transcripts were found in 18/24 (75%) of the tumors while SYT-SSX2 transcripts were identified in 3/24 (12.5%). All of the poorly differentiated tumors and seven out of eight tumors from patients who developed lung metastases had an SYT-SSX1 fusion transcript. Real-time PCR is useful in detecting and distinguishing SYT-SSX1 from SYT-SSX2 gene fusions in synovial sarcoma. Valuable aspects of this methodology are the applicability to both frozen and formalin-fixed samples, decreased labor costs, and the rapidity of results. In addition, distinguishing SYT-SSX1 from SYT-SSX2 fusions with these methods allow for prospective collection of information that may clarify issues of prognostic relevance.