Competitive Risk Analysis of Prognosis in Patients With Cecum Cancer: A Population-Based Study.

BACKGROUND: The presence of competing risks means that the results obtained using the classic Cox proportional-hazards model for the factors affecting the prognosis of patients diagnosed with cecum cancer (CC) may be biased. OBJECTIVE: The purpose of this study was to establish a competitive risk model for patients diagnosed with CC to evaluate the relevant factors affecting the prognosis of patients, and to compare the results with the classical COX proportional risk model. METHODS: We extracted data on patients diagnosed with CC registered between 2004 and 2016 in the Surveillance, Epidemiology, and End Results (SEER) database. The univariate analysis utilized the cumulative incidence function and Gray's test, while a multivariate analysis was performed using the Fine-Gray, cause-specific (CS), and Cox proportional-hazards models. RESULTS: The 54463 eligible patients diagnosed with CC included 24387 who died: 12087 from CC and 12300 from other causes. The multivariate Fine-Gray analysis indicated that significant factors affecting the prognosis of patients diagnosed with CC include: age, race, AJCC stage, differentiation grade, tumor size, surgery, radiotherapy, chemotherapy and regional lymph nodes metastasis. Due to the presence of competitive risk events, COX model results could not provide accurate estimates of effects and false-negative results occurred. In addition, COX model misestimated the direction of association between regional lymph node metastasis and cumulative risk of death in patients diagnosed with CC. Competitive risk models tend to be more advantageous when analyzing clinical survival data with multiple endpoints. CONCLUSIONS: The present study can help clinicians to make better clinical decisions and provide patients diagnosed with CC with better support.

A population-based study on the prognostic impact of primary tumor sidedness in patients with peritoneal metastases from colon cancer.

Primary tumor location is an established prognostic factor in patients with (metastatic) colon cancer. Colon tumors can be divided into left-sided and right-sided tumors. The aim of this study was to determine the impact of primary tumor location on treatment and overall survival (OS) in patients with peritoneal metastases (PM) from colon cancer. This study is a retrospective, population-based cohort study. Records of patients diagnosed with colon cancer and synchronous PM, from 1995 through 2016, were retrieved from the Netherlands Cancer Registry (NCR). Data on diagnosis, staging, and treatment were extracted from the medical records by specifically trained NCR personnel. Information on survival status was updated annually using a computerized link with the national civil registry. In total, 7930 patients were included in this study; 4555 (57.4%) had a right-sided and 3375 (42.6%) had a left-sided primary tumor. In multivariable analysis right-sided primary tumor was associated with worse OS (HR: 1.11, 95% CI 1.03-1.19, P = .007). Of all patients diagnosed with PM, 564 (7.1%) underwent cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS-HIPEC). Patients with left-sided primary tumors were more often candidates for CRS-HIPEC (6.5% vs. 8.0%, P = .008). OS of patients with right- and left-sided tumors who underwent CRS-HIPEC did not significantly differ. In conclusion, primary right-sided colon cancer was an independent prognostic factor for decreased OS in patients diagnosed with synchronous PM. In patients treated with CRS-HIPEC location of the primary tumor did not influence survival.

Primary Pediatric Non-Hodgkin Lymphomas of the Gastrointestinal Tract: A Population-based Analysis.

BACKGROUND/AIM: The aim of this study was to present the clinical characteristics, natural history and survival outcomes of primary gastrointestinal non-Hodgkin lymphomas (PGINHL) in the pediatric population. PATIENTS AND METHODS: Surveillance, Epidemiology, and End Results (SEER) database was queried for patients aged 0 to 19 years with PGINHL between 1973 and 2014. RESULTS: A total of 452 cases were identified [mean age 11.0 (±5.1)] years, whites 84.1%, males (76.5%). The majority of tumors were noted in the small bowel (SB) (47.6%), followed by large bowel (LB) (28.5%) and the stomach (10.0%). Overall, the most common histological subtype was Burkitt lymphoma (51.8%), followed by diffuse large B-cell lymphoma (DLBCL) (26.1%). Mean overall survival (OS) of the entire cohort was 33,33 years with a 5-yr, 10-yr and 30-yr survival rate of 86%, 86% and 79%, respectively. Large bowel tumors had the best long-term survival rates whereas; gastric tumors had the worst with 30-yr survival rate 84% and 74%, respectively. Overall, 328 (72.6%) patients received surgery. No significant survival difference was noted between patients who underwent surgery and those who did not. CONCLUSION: This study presents the largest dataset of pediatric PGINHL and describes the clinical features and outcomes of these patients in addition to summarizing the literature.

[Prognostic analysis of colon and rectal neuroendocrine neoplasm in different stages].

Objective: To explore the survival difference of patients with colon and rectal neuroendocrine neoplasm (NEN) at different stages. Methods: We identified 8 679 patients with colorectal NEN diagnosed between 1988 and 2014 from the Surveillance, Epidemiology, and End Results (SEER) registry, including 5 437 rectal NEN and 3 242 colon NEN ( 1 681 cecum NEN ). Survival curve was drawn by Kaplan-Meier method. Prognostic factors were analyzed by univariate analysis and multivariate Cox regression model. Results: The ratio of male patients with colon and rectal NEN was similar to female (P=0.095). Rectal NEN patients were younger (P<0.001), more highly differentiated (P<0.001), and with earlier stage (P<0.001). Survival analysis showed that the survival of rectal NEN was superior to that of colon NEN, with 10-year tumor-specific survival rates of 86.8% and 44.8% respectively (P<0.001). Multivariate Cox analysis showed that age, gender, marital status, primary tumor site, grade, stage and surgery were independent prognostic factors of colorectal NEN (all P<0.01). The most important factor was stage (HR=3.531), followed by differentiation grade (HR=1.856). Stratified analysis displayed that the survival of rectal NEN in stage Ⅰ, Ⅱ and Ⅳ were better than those of corresponding stage of colon NEN (all P<0.05), but worse in stage Ⅲ (P=0.012). While the survival of rectal NEN were significantly better than those of colon NEN within all stages after excluding 1681 cases of cecal NEN (all P<0.05). Among the patients with well-differentiated NEN, the survival of rectal NEN in stage Ⅰ, Ⅲ and Ⅳ were better than those of corresponding stage of colon NEN (all P<0.05) while there was no significant difference in stage Ⅱ(P=0.169). For poor-differentiated NEN, only the survival of rectal NEN patients in stage Ⅳ (P=0.001) was significant longer than those of colon NEN, while there was no significant difference in stage Ⅰ, Ⅱ and Ⅲ (stage Ⅰ: P=0.760; stage Ⅱ: P=0.181; stage Ⅲ: P=0.313). Conclusions: The survival of NEN patients in colon and rectum is different. Cecum NEN should be considered as a separated tumor for prognostic analysis due to its special clinicopathologic characteristics.

Site-specific Differences in Colonic Adenocarcinoma: KRAS Mutations and High Tumor Budding Are More Frequent in Cecal Adenocarcinoma.

Recent literature indicates that adenocarcinomas of the cecum differ with respect to molecular alterations compared with noncecal proximal colon adenocarcinomas and that cecal tumor site may be a prognostically relevant variable. We compared molecular alterations, histopathologic features, and disease-specific survival in a series of 328 colonic adenocarcinomas identified over a 2-year period and stratified by tumor location (cecum, right colon, and left colon). Overall, cecal adenocarcinomas demonstrated the highest frequency of molecular abnormalities with 74% harboring either a KRAS exon 2 or 3 mutation, a BRAF mutation, or DNA mismatch repair protein deficiency. KRAS mutations were more frequently seen in the cecum compared with all other tumor sites (P=0.03). KRAS mutations were identified in 46% of cecal adenocarcinomas compared with only 25% of adenocarcinomas of the right colon (P=0.004). Cecal adenocarcinomas more frequently displayed adverse histopathologic features, in particular high tumor budding (31%), compared with tumors of the right colon (18%; P=0.04) and tumors of the left colon (17%; P=0.02). Overall stage was the most important independent predictor of disease-specific survival in the multivariable analysis; however, cecal tumor site and high tumor budding were also predictive of poor survival, particularly in patients with stage III or IV tumors. In conclusion, cecal adenocarcinomas are characterized by a high frequency of KRAS mutations compared with noncecal right colon tumors, frequently display high tumor budding, and may be a prognostically relevant variable, particularly in patients with stage III or IV disease.

Right colon cancer: Left behind.

INTRODUCTION: Prognosis of colon cancer (CC) has steadily improved during the past three decades. This trend, however, may vary according to proximal (right) or distal (left) tumor location. We studied if improvement in survival was greater for left than for right CC. METHODS: We included all CC recorded at the Geneva population-based registry between 1980 and 2006. We compared patients, tumor and treatment characteristics between left and right CC by logistic regression and compared CC specific survival by Cox models taking into account putative confounders. We also compared changes in survival between CC location in early and late years of observation. RESULTS: Among the 3396 CC patients, 1334 (39%) had right-sided and 2062 (61%) left-sided tumors. In the early 1980s, 5-year specific survival was identical for right and left CCs (49% vs. 48%). During the study period, a dramatic improvement in survival was observed for patients with left-sided cancers (Hazard ratio [HR]: 0.42, 95% confidence interval [CI]: 0.29-0.62, p < 0.001) but not for right CC patients (HR: 0.76, 95% CI: 0.50-1.14, p = 0.69). As a consequence, patients with distal CC have a better outcome than patients with proximal CC (HR for left vs. right CC: 0.81, 95% CI: 0.72-0.90, p < 0.001). CONCLUSION: Our data indicate that, contrary to left CC, survival of patients with right CC did not improve since 1980. Of all colon cancer patients, those with right-sided lesions have by far the worse prognosis. Change of strategic management in this subgroup is warranted.

A randomised, open-label phase II trial of afatinib versus cetuximab in patients with metastatic colorectal cancer.

PURPOSE: This randomised phase II trial aimed to compare efficacy of the irreversible ErbB family blocker, afatinib, with cetuximab in patients with KRAS wild-type metastatic colorectal adenocarcinoma (mCRC) with progression following oxaliplatin- and irinotecan-based regimens. Efficacy in patients with KRAS mutations was also evaluated. PATIENTS AND METHODS: Patients with KRAS wild-type tumours were randomised 2:1 to afatinib (40 mg/day, increasing to 50 mg/day if minimal toxicity) or cetuximab weekly (400 mg/m2 loading dose, then 250 mg/m2/week) according to number of previous chemotherapy lines. All patients with KRAS-mutated tumours received afatinib. Primary end-points were objective response (OR) for the wild-type group and disease control for the KRAS-mutated group. Secondary end-points were progression-free survival (PFS) and overall survival (OS). RESULTS: Patients with KRAS wild-type tumours (n=50) received afatinib (n=36) or cetuximab (n=14). Unconfirmed and confirmed ORs were 3% and 0% for afatinib versus 20% and 13% for cetuximab (odds ratio: 0.122 [P=0.0735] and <0.001, respectively). Median PFS was 46.0 and 144.5 days for afatinib and cetuximab, respectively. Median OS was 355 days with afatinib but not reached for cetuximab. In the KRAS-mutated group (n=41), five (12%) patients achieved confirmed disease control (stable disease; P=0.6394 [comparison versus 10%]); no ORs were reported. Median PFS and OS were 41.0 and 173days, respectively. Most frequent treatment-related adverse events were diarrhoea and rash across groups. CONCLUSIONS: The efficacy of afatinib was inferior to cetuximab in patients with KRAS wild-type mCRC. In patients with KRAS-mutated tumours, disease control was modest with afatinib. Afatinib had a manageable safety profile.

Long-term survival of a patient with metachronous rectal metastasis from primary cecal cancer who underwent repetitive resection and chemotherapy: a case report.

There are few reported cases of colorectal metastasis from cancers of other organs, particularly other segments of the colon. Here we describe the long-term survival of a 68-year-old male patient with metachronous rectal metastasis from cecal cancer who underwent repetitive resection and chemotherapy. The patient underwent ileocecal resection and hepatectomy for cecal cancer with liver metastasis (T3, N1a, M1a, Stage IVA) in 2006. The patient subsequently underwent splenectomy for splenic metastasis in 2007. In August 2008, barium enema revealed compression of the rectal wall, and abdominal computed tomography (CT) detected a mass along the rectum extending into the pelvis. Rectal metastasis from cecal cancer was suspected and Hartmann's operation with bilateral seminal vesicle dissection was performed. Histological examination of the excised tumor revealed moderately differentiated adenocarcinoma formed in the muscularis propria of the rectum and infiltrating the connective tissue between the seminal vesicle and rectum. However, no tumor was detected in the rectal mucosa or submucosa. These histological findings supported the diagnosis of rectal metastasis from cecal cancer. The patient has been monitored at our clinic for 60 months after surgical removal of the rectal metastasis. The findings from this case should alert oncologists to the potential danger of rectal metastasis from primary colon cancer and the benefits of timely complete resection in terms of improved patient outcomes.

[Gastrointestinal Epstein Barr virus positive diffuse large B cell lymphoma in elderly: report of five cases and review of literature]. / Linfoma de celulas grandes B difuso gastrointestinal del anciano asociado al virus Epstein Barr: reporte de cinco casos y revision de la literatura.

EBV-positive diffuse large B-cell lymphoma (DLBCL) in elderly is a new entity included provisionally in the most recent WHO Classification of lymphoid neoplasms. It usually affects elderly patients and has a poor survival. The goal of this report was to evaluate clinical, endoscopic characteristics and survival of five patients with this entity and gastrointestinal afectation. From five cases, three cases had gastric infiltration, one ileon and one in cecum.

Linfoma de Celulas Grandes B Difuso Gastrointestinal del Anciano Asociado al Virus Epstein Barr: Reporte de Cinco Casos y Revision de la Literatura / Gastrointestinal Epstein Barr Virus positive diffuse large B cell lymphoma in elderly: report of five cases and review of literatura

El Linfoma de Células Grandes B difuso del anciano asociado al Epstein Barr es una nueva entidad incluida provisionalmente en la más reciente clasificación de neoplasias linfoides de la WHO. Usualmente afecta ancianos y tiene pobre sobrevida. El objetivo de este reporte fue evaluar las característica clínicas, endoscópicas y sobrevida de cinco pacientes portadores de esta entidad y compromiso gastrointestinal. Tres casos tuvieron infiltración gástrica y dos casos tuvieron compromiso del ileón y el ciego.

EBV-positive diffuse large B-cell lymphoma (DLBCL) in elderly is a new entity included provisionally in the most recent WHO Classification of lymphoid neoplasms. It usually affects elderly patients and has a poor survival. The goal of this report was to evaluate clinical, endoscopic characteristics and survival of five patients with this entity and gastrointestinal afectation. From five cases, three cases had gastric infiltration, one ileon and one in cecum.

[Results of surgical treatment of locally-spread colorectal cancer].

During the period from 2001 to 2005 operations were performed on 186 patients with locally-spread colorectal cancer. In 132 cases (the 1st group) radical combined resections were performed, 54 patients (the 2nd group) underwent palliative operations. The morbidity rate was 18.2% (24 cases) in the first group and 7.4% (4 cases) in the second group. The mortality rate in the first group was 2.3% (3 cases), no mortality was observed in the second group. Overall 3-year survival in the first group was 69.9%, and no one patient of the second group survived longer than 3 years. Overall 5-year survival in the first group was 54.7%, and the relapse-free 5-year survival was 52.8%. The data obtained have shown the effectiveness of combined resections in treatment of locally-spread colorectal cancer. We suggest that further improvement of long-term results can be achieved using chemoradiation.

The value of (18)F-fluorodeoxyglucose positron emission tomography/computed tomography for staging of primary extranodal head and neck lymphomas.

OBJECTIVES/HYPOTHESIS: Using a retrospective approach, the aim of this study was to confirm the previously described value of fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography ((18)F-FDG-PET/CT) in patients with primary extranodal lymphoma of the head and neck region. Additionally, the clinical significance of the semiquantitative analysis of the standardized uptake value (SUV), its predictive role in the follow-up setting, and its value in detection of synchronous primaries were studied. STUDY DESIGN: Retrospective chart review. METHODS: Twenty-six patients with a primary extranodal head and neck lymphoma (22 diffuse large B-cell lymphoma, one Hodgkin's lymphoma, three malignant T-cell lymphomas) were included. We retrospectively evaluated the clinical outcomes according to the maximum standardized uptake values of the primary lesion (SUV(max)) and whether a positron emission tomography/computed tomography (PET/CT) was performed or not in the follow-up studies. The median SUV(max) was chosen as the cutoff value. The patients were then grouped as those with either low or high SUV(max), respective to the cutoff value. Event-free survival and cumulative survival were endpoints of interest. RESULTS: Nineteen patients (73%) were above the age of 60 years; the median age was 70 years (range, 28-87 years). Most primary sites were in the Waldeyer's ring (15 patients, 60%), whereas in four patients (27%) only the palatine tonsil was affected. The SUV(max) ranged from 5.8 to 33.9. In one patient, relevant fluorodeoxyglucose (FDG) uptake within the intestine revealed a cecal adenocarcinoma as a secondary primary. Twenty of the 25 clinically followed patients (80%) achieved complete remission after treatment. Patients with high SUV(max) showed favorable survival (log-rank test, P = .044). A tendency for longer survival within the group with follow-up PET/CT studies could be noted but with no significant statistical difference (P = .349). CONCLUSIONS: (18)F-FDG-PET/CT imaging is a potent primary staging tool. It also has application as an instrument for evaluation of follow-up and response to therapy in patients suffering from primary extranodal lymphoma and for detection of secondary malignancies. Furthermore, (18)F-FDG uptake by the primary lesion may be related to better survival.

Effect of obstruction on morbidity and mortality in patients with right-sided colon carcinoma: a case-matched study.

In this retrospective case-matched study, our aim was to assess the influence of an obstruction on mortality, morbidity, and long-term survival in patients with right-sided colon cancer. Thirty-seven patients who had undergone curative emergency surgery for the treatment of right-sided colon cancer were matched according to age, American Society of Anesthesiology score, and disease stage with 37 control patients who had undergone curative elective surgery, and the outcomes were compared. There was a trend toward a higher rate of recurrence and a lower rate of survival in patients with an obstruction; however, the difference was not statistically significant. The only independent prognostic factor was tumor site, with hepatic flexure tumors having the worst results. Emergency surgery performed to treat an obstruction does not negatively influence early postsurgical morbidity and mortality. Survival of patients with obstructive colorectal cancer is correlated with certain pathological variables and less strongly associated with clinical variables.

Retroperitoneal margin involvement by adenocarcinoma of the caecum and ascending colon: what does it mean?

OBJECTIVE: Circumferential margin involvement (CRM) is a powerful predictor of local recurrence, distant metastasis and patient survival in rectal cancer. In this study, we aimed to determine the frequency of retroperitoneal margin involvement in right colon cancer and describe its relationship to tumour stage and outcome of surgical treatment. METHOD: Two hundred and twenty-eight consecutive resections for adenocarcinoma of the ascending colon and caecum were identified between 1998 and 2006. Tumour involvement of the posterior retroperitoneal surgical resection margin (RSRM) was recorded and correlated with tumour stage, grade and clinical outcome. RSRM positive patients were compared with CRM positive rectal tumours resected in the same surgical unit. RESULTS: Nineteen of 228 right hemicolectomies (8.4%) showed tumour involvement of the RSRM (defined as < or = 1 mm). Approximately half of the RSRM positive patients underwent palliative resections because of synchronous distant metastases. Out of nine 'potentially curative' resections where the RSRM was involved, five patients subsequently developed metastatic recurrence and two isolated local recurrence. RSRM positivity was associated with advanced tumour stage and more extensive extramural spread than CRM positive rectal cancers. CONCLUSION: Retroperitoneal surgical resection margin involvement by caecal and ascending colon carcinoma is a marker of advanced tumour stage and associated with a high incidence of synchronous and metachronous distant metastasis. More aggressive surgery to obtain a clear margin or postoperative radiotherapy to the tumour bed is likely to benefit only a minority of patients.

Intestinal marginal zone B-cell lymphoma of MALT type: clinical manifestation and outcome of a rare disease.

Intestinal marginal zone B-cell lymphoma of the MALT type (I-MZL) is a relatively uncommon form of lymphoma. Twenty-seven patients with histologically-confirmed I-MZL were analyzed. The patients initially presented with abdominal pain (62.9%), and diarrhea (22.2%). The most common involved site was the ileo-caecal area (40.7%). Musshoff's stage I(E), II(E)1, II(E)2, III(E) and IV were present in 44%, 15%, 11%, 7.4% and 22% respectively. Sixty-three percent were in the low-risk group according to the Follicular Lymphoma International Prognostic Index. Complete response and partial response were achieved in 82% and 4% patients. The estimated 5-year overall survival (OS) and progression-free survival (PFS) rates were 86% and 54%. Stage > or = II(E)2 was determined to be a poor prognostic factor for PFS and OS. I-MZL commonly manifests in an early-stage, low-risk state and tends to respond well to local and systemic treatment with favorable prognosis. I-MZL tends to be an indolent disease - characterized by prolonged survival with frequent relapses, similarly to other site MZLs.

Malignant ileocaecal serotonin-producing carcinoid tumours: the presence of a solid growth pattern and/or Ki67 index above 1% identifies patients with a poorer prognosis.

Patients with malignant serotonin-producing carcinoid tumours in the jejunum, ileum and caecum generally have long survival expectancy. In some patients, however, tumour progression is more rapid and there is a need to identify them at an early stage. The purpose of this study was to determine if histopathological characteristics and/or Ki67 and apoptotic indices are of prognostic value in cases of metastatic disease. Eighty-one patients with this tumour were included in the study; all had metastases and their survival range was 1-223 months. Five growth patterns were identified and described. For 57 patients whose tumour material was available, the Ki67 and apoptotic indices were calculated for ten randomly selected tumour areas and 'hot spots'. A Cox regression analysis was used to test if histopathology and/or Ki67 index >/=1% could identify patients whose survival might be shorter than anticipated. One of the histopathological growth patterns-the solid (non-organoid) cell pattern-was correlated to shorter survival in both primary tumours and metastases, when compared with the organoid growth patterns (hazard ratio 2.9 and 2.3, p/=1%, in both primary tumour and metastases, identified patients at increased risk of shorter survival (hazard ratio 5.4 and 2.5, p/=1%, can be used to identify patients with a poorer prognosis. This study also showed that Ki67 index <2% cannot, as previously suggested, be used to indicate a benign progression for this tumour category.

[A case of disseminated tumor from cecal cancer with survival for over 5 years after twice surgical resection and systemic chemotherapy].

A 66-year-old man underwent a curative operation for cecal cancer on the 30th of November, 1998. Since his CEA level rose in January 2001, computed tomography (CT) revealed a tumor in the abdomen. He underwent a resection of this tumor and disseminated tumors that were diagnosed during the operation. He received systemic chemotherapy (5'-DFUR 600 mg 3x everyday, CPT-11 80 mg/body div every 2 weeks), but the CEA level rose again in August 2003. He was diagnosed with spleen metastasis and underwent splenectomy. The tumor disseminated in the left diaphragm was also resected. After that, he received systemic chemotherapy (5-FU 500 mg/body/week div, levofolinate calcium 250 mg/body/week i.v.) as an outpatient. Peritoneal carcinomatosis from colorectal cancer with distant metastasis, in general, has no indication for an operation. However, if dissemination is located after a sufficient observation period, its resection may be recommended.

Gastrointestinal glomus tumors: a clinicopathologic, immunohistochemical, and molecular genetic study of 32 cases.

Glomus tumors usually occur in the peripheral soft tissues, but similar tumors have also been reported in the stomach and occasionally in the intestines. However, the relationship of these tumors to peripheral glomus tumors and gastrointestinal stromal tumors has not been fully clarified because previous series of gastrointestinal glomus tumors predate availability of immunohistochemistry. This clinicopathologic study examined 32 gastrointestinal glomus tumors. All but one of the tumors were located in the stomach and the remaining tumor was from the cecum. The tumors occurred with a strong female predominance (23 females and 9 males) and a median age of 55 years (range 19-90 years). The gastric tumors typically presented with gastrointestinal bleeding or ulcer-like symptoms, and 14 tumors had mucosal ulceration. Five tumors were incidental findings. The tumor sizes varied from 1.1 to 7 cm (median 2 cm), and most were located in the antrum. Histologically, the tumors typically had a solid pattern of sharply demarcated, round glomus cells with prominent, mildly dilated pericytoma-like vessels. Vascular invasion and focal atypia were relatively common (seen in 11 and 13 cases, respectively), and low mitotic activity (1-4 per 50 high power fields), was seen in 10 cases. Immunohistochemically, all tumors were positive for alpha-smooth muscle actin and calponin, and nearly all had a net-like pericellular laminin and collagen type IV positivity. All tumors were negative for desmin and S-100 protein. Three tumors had focal synaptophysin positivity, but none was positive for chromogranin. All tumors lacked KIT expression and the GIST-specific mutations in the c-kit gene. Follow-up revealed one patient death of metastatic disease to liver at 50 months; this tumor had 1 mitosis per 50 high power fields, but had spindle cell foci, mild atypia, and vascular invasion. Thirteen patients were well and alive after long-term follow-up. Gastrointestinal glomus tumors occur almost exclusively in the stomach, and they have a good overall prognosis, but a small, unpredictable potential for malignant behavior exists. These tumors are phenotypically similar to peripheral glomus tumors and differ from epithelioid GISTs.

Survival of colorectal cancer patients in Singapore by anatomic subsite: a population-based study.

INTRODUCTION: Studies of the prognostic value of anatomic subsite in colorectal cancer survival have yielded conflicting results. Two explanations for possible differences in survival patterns between proximal and distal lesions in the colorectum are biological difference between subsites and the presence of more early-stage lesions in distal than in proximal large bowel. MATERIALS AND METHODS: A total of 435 cases with proximal lesions and an equal number with distal lesions diagnosed between 1990 and 1992 were randomly selected from the Singapore Cancer Registry. Information on vital status at 31 December 1996 were obtained by computerised matching with data from the National Registry of Births and Deaths. RESULTS: Persons with proximal cancers in our study population did not present at a later stage than persons with distal cancer, local lesions (Dukes' Stage A + B) being 45.5% and 45.1%, respectively. Our analysis showed no significant differences in survival between subsites on a stage-for-stage basis. The 5-year survival rates were 42% and 44% for proximal and distal lesions, respectively (median survival times 3.98 and 4.27 years). Stage at diagnosis was the strongest predictor of survival. Among proximal lesions, 5-year survival rates were 57%, 36% and 12% for local, regional and metastatic lesions, respectively. The corresponding figures for the distal group were 65%, 37% and 10%. Age at diagnosis had a significant influence on survival. CONCLUSIONS: Our results, based on population-based figures on survival of colorectal cancer patients where the impact of screening has not been large, do not support an independent influence of anatomic subsite in predicting survival of colorectal cancer.

Highly aggressive behavior and poor prognosis of small-cell carcinoma in the alimentary tract: flow-cytometric analysis and immunohistochemical staining for the p53 protein and proliferating cell nuclear antigen.

The purpose of this study was to determine the clinical course, and effects of the histopathologic characteristics of specific tumors, including DNA contents and immunohistochemical aspects, in patients with small-cell carcinoma of the alimentary tract. Medical records of 14 patients who presented with small-cell carcinoma of the alimentary tract were retrospectively reviewed. Primary tumors were studied by immunohistochemical and flow cytometric analyses. Of these 14 small-cell carcinomas, 4 were esophageal, 8 gastric, and 2 colonic tumors. DNA aneuploidy was observed in 8 tumors. Staining for the p53 product was positive in 57.1% of all the tumors. The average proliferating cell nuclear antigen (PCNA) labeling rate (LR) was 72.4 +/- 11.6%. The average PCNA LR was significantly higher for the p53-positive group (p < 0.05). The estimated median survival was 253 days for all patients. Noncurative resection was associated with a significantly less favorable prognosis (p < 0.01). Distant metastases were observed in 13 of 14 patients. A higher PCNA LR of small-cell carcinoma may be an unfavorable characteristic of biological behavior. The patients with disseminated disease should undergo a symptomatically palliative operation combined with chemotherapy.