MSH3: a confirmed predisposing gene for adenomatous polyposis.

BACKGROUND: The MSH3 gene is part of the DNA mismatch repair system, but has never been shown to be involved in Lynch syndrome. A first report of four patients from two families, bearing biallelic MSH3 germline variants, with a phenotype of attenuated colorectal adenomatous polyposis raised the question of its involvement in hereditary cancer predisposition. The patients' tumours exhibited elevated microsatellite alterations at selected tetranucleotide repeats (EMAST), a hallmark of MSH3 deficiency. METHODS: We report five new unrelated patients with MSH3-associated polyposis. We describe their personal and familial history and study the EMAST phenotype in various normal and tumour samples, which are relevant findings based on the rarity of this polyposis subtype so far. RESULTS: All patients had attenuated colorectal adenomatous polyposis, with duodenal polyposis in two cases. Both women had breast carcinomas. EMAST phenotype was present at various levels in different samples of the five patients, confirming the MSH3 deficiency, with a gradient of instability in polyps depending on their degree of dysplasia. The negative EMAST phenotype ruled out the diagnosis of germline MSH3 deficiency for two patients: one homozygous for a benign variant and one with a monoallelic large deletion. CONCLUSION: This report lends further credence to biallelic MSH3 germline pathogenic variants being involved in colorectal and duodenal adenomatous polyposis. Large-scale studies may help clarify the tumour spectrum and associated risks. Ascertainment of EMAST may help with the interpretation of variants of unknown significance. We recommend adding MSH3 to dedicated diagnostic gene panels.

Time-Dependent Efficacy of Checkpoint Inhibitor Nivolumab: Results from a Pilot Study in Patients with Metastatic Non-Small-Cell Lung Cancer.

HYPOTHESIS: Prior experimental and human studies have demonstrated the circadian organization of immune cells' proliferation, trafficking, and antigen recognition and destruction. Nivolumab targets T(CD8) cells, the functions, and trafficking of which are regulated by circadian clocks, hence suggesting possible daily changes in nivolumab's efficacy. Worse progression-free survival (PFS), and overall survival (OS) were reported for malignant melanoma patients receiving more than 20% of their immune checkpoint inhibitor infusions after 16:30 as compared to earlier in the day. METHODS: Consecutive metastatic non-small-cell cancer (NSCLC) patients received nivolumab (240 mg iv q 2 weeks) at a daily time that was 'randomly' allocated for each course on a logistical basis by the day-hospital coordinators. The median time of all nivolumab administrations was computed for each patient. The study population was split into two timing groups based upon the median value of the median treatment times of all patients. CTCAE-toxicity rates, iRECIST-tumor responses, PFS and OS were computed according to nivolumab timing. PFS and OS curves were compared and hazard ratios (HR) were computed for all major categories of characteristics. Multivariable and sensitivity analyses were also performed. RESULTS: The study accrued 95 stage-IV NSCLC patients (PS 0-1, 96%), aged 41-83 years. The majority of nivolumab administrations occurred between 9:27 and 12:54 for 48 patients ('morning' group) and between 12:55 and 17:14 for the other 47 ('afternoon' group). Median PFS (95% CL) was 11.3 months (5.5-17.1) for the 'morning' group and 3.1 months (1.5-4.6) for the 'afternoon' one (p < 0.001). Median OS was 34.2 months (15.1-53.3) and 9.6 months (4.9-14.4) for the 'morning' group and the 'afternoon' one, respectively (p < 0.001). Multivariable analyses identified 'morning' timing as a significant predictor of longer PFS and OS, with respective HR values of 0.26 (0.11-0.58) and 0.17 (0.08-0.37). The timing effect was consistent across all patient subgroups tested. CONCLUSIONS: Nivolumab was nearly four times as effective following 'morning' as compared to 'afternoon' dosing in this cohort of NSCLC patients. Prospective timing-studies are needed to minimize the risk of resistance and to maximize the benefits from immune checkpoint inhibitors.

Over 90% of cases of Microscopic Colitis can be diagnosed by performing a short colonoscopy.

AIMS: To determinate the topographical distribution of key diagnostic histological features of lymphocytic colitis (LC) and collagenous colitis (CC) and to establish what correlations may exist between the histological findings and the causes and severity of MC. PATIENTS AND METHODS: Patients with MC were included in a prospective multicentre French study from September 2010 to October 2012. MC was diagnosed by performing total colonoscopy with multiple biopsies of the rectum and colon collected in separate jars and analyzed separately for each site (descending and sigmoid colon, transverse colon, ascending colon). CC was defined as a subepithelial collagen layer>10µm thick and LC as an intraepithelial lymphocyte (IEL) count>20 lymphocytes per 100 epithelial cells without any associated thickening of the subepithelial collagen. RESULTS: Ninety-five patients, 69 with LC 26 and with CC, were included in the analysis. The sensitivity of the biopsies for diagnosing MC was maximum in the transverse colon and minimum in the rectum. Rectal and left colonic biopsies resulted in the diagnosis of CC and CL in 93% and 94% of cases, respectively. All the remaining cases of MC were diagnosed by performing additional biopsies beyond the splenic flexure. In patients with LC, a higher rate of IELs was associated with the absence of abdominal pain (P=0.01) and a shorter duration of diarrhea (P=0.001). In patients with CC, a lower level of collagen thickness in the basement membrane was associated with the presence of an autoimmune disease (P=0.02). CONCLUSION: More than 90% of cases of microscopic colitis were diagnosed in this study by performing rectal and left colonic biopsies.

High prevalence of deficient mismatch repair phenotype and the V600E BRAF mutation in elderly patients with colorectal cancer.

AIMS: Colorectal cancer (CRC) occurs mostly in the elderly. However, the biology of CRC in elderly has been poorly studied. This study examined the prevalence of deficient mismatch repair phenotype (dMMR) and BRAF mutations according to age. PATIENTS AND METHODS: MMR phenotype was prospectively determined by molecular analysis in patients of all ages undergoing surgery for CRC. BRAF V600E mutation status was analysed in a subset of dMMR tumours. RESULTS: A total of 754 patients who underwent surgery between 2005 and 2008 were included in the study. Amongst them, 272 (36%) were ≥75years old. The proportion of women <75 was 38% and that ≥75 was 53% (p<0.0001). The prevalence of dMMR was 19.4% in patients ≥75 and 10.7% in patients <75 (p=0.0017). For patients ≥75, the prevalence of dMMR was significantly higher in women than in men (27% vs 10.2%, respectively; p=0.003) but was similar in women and men <75 (12.5% vs 9.7%, respectively; p=0.4). We examined BRAF mutation status in 80 patients with dMMR tumours. The V600E BRAF mutation was significantly more frequent in patients ≥75 than in patients <75 (72.2% vs 11.4%, respectively; p<0.001). In patients ≥75, there was no difference in the prevalence of the BRAF V600E mutation according to sex (78% in women and 70% in men, p=0.9). CONCLUSIONS: The prevalence of dMMR in CRC is high in patients over 75. In elderly patients, dMMR tumours are significantly more frequent in women than in men. The BRAF mutation is frequent in elderly patients with CRC.

Deficient mismatch repair phenotype is a prognostic factor for colorectal cancer in elderly patients.

OBJECTIVE: About 15% of colorectal adenocarcinomas have a deficient DNA mismatch repair phenotype. The frequency of deficient DNA mismatch repair tumours increases with age due to the hypermethylation of hMLH1 promoter. The study aimed to determine the prognostic value of deficient DNA mismatch repair phenotype in elderly patients. DESIGN: Mismatch repair phenotype was retrospectively determined by molecular analysis in consecutive resected colorectal adenocarcinoma specimens from patients over 75 years of age from 4 Oncology centres. RESULTS: 231 patients (median age: 81, range: 75-100) were enrolled from 2005 to 2008. Mean prevalence of deficient DNA mismatch repair phenotype was 22.5%, and 36% for patients over 85 years. Deficient DNA mismatch repair status was significantly associated with older age, female sex, proximal colon primary and high grade tumour. For stage II tumours no deficient DNA mismatch repair tumours had a recurrence at end of follow-up compared to 17% for tumours with proficient phenotype. The proficient phenotype status was significantly associated with worse age-adjusted overall survival [HR 2.60; 95% CI 1.05-6.44; p=0.039]. For stage III tumours a trend for less recurrence was observed for deficient DNA mismatch repair phenotype (16%) compared to proficient phenotype (36%). CONCLUSION: deficient DNA mismatch repair phenotype is a prognostic factor in stage II colorectal tumour in elderly patients. Our results suggest that mismatch repair phenotype should be taken in consideration for adjuvant chemotherapy decision in elderly patients.

Chronic monoarthritis and previous history of cancer: think about synovial metastasis.

Synovial metastases are rare events. Only 37 cases diagnosed by synovial fluid cytologic examination and/or by microscopic investigation of synovial biopsies have been previously reported in the literature. We report another case of shoulder chronic arthritis due to a recurrence of rectal adenocarcinoma and review previous published observations. Generally, this condition carries a poor prognosis with average patients survival of less than 5 months. The possibility of metastatic disease should be considered when an elderly person or patient with a history of previous malignancy presents with a chronic arthritis.

Pleomorphic hyalinizing angiectatic tumor of soft parts: ultrastructural analysis of a case with original features.

Pleomorphic hyalinizing angiectatic tumor, a rare neoplasm of uncertain lineage resembling malignant fibrous histiocytoma and schwannoma, was first described in 1996 by M. E. F. Smith et al. (Am Surg Pathol. 20:21-29). To date, less than 100 cases have been reported in the international literature. It occurs in subcutaneous and intramuscular soft tissues of extremities or trunk in adults without sex predilection. All lesions are composed of sheets and fascicles of spindled and pleomorphic cells associated with clusters of thick-walled ectatic vessels surrounded by a perivascular hyaline material and inflammatory cells such as mast cells. About one-half of these neoplasms express CD34. No patient has developed metastases but occasional local recurrences are possible. This tumor of uncertain lineage is suggested to be an aggressive locally growing low-grade sarcoma. Only 3 cases were previously studied by electron microscopy and appeared to consist of primitive fibroblastic cells. The authors report histological and ultrastructural characteristics of a new case of PHAT excised from the right buttock of a 66-year-old man with the presence of ganglion-like cells, a feature that has not been previously reported, and unusual central ischemic necrosis. The features of this case are suggestive of a fibroblastic origin.

[Post-cholecystectomy amputation neuroma of the common bile duct with obstructive jaundice]. / Sténose post-opératoire de la voie biliaire principale due à un névrome d'amputation post-cholécystectomie.

Amputation neuroma of the common bile duct after surgery is a rare and mostly asymptomatic lesion. A 60-year old patient presented with obstructive jaundice three months after a cholecystectomy for symptomatic gallstones. Imaging investigations showed common extrahepatic bile duct stenosis. Surgical resection of the stricture with biliodigestive anastomosis was performed. Histological examination of the surgical specimen revealed an amputation neuroma. Despite its rarity, amputation neuroma of the common bile duct should be considered in patients with post-cholecystectomy syndrome following liver or extrahepatic bile duct surgical procedures.

Implication of tumstatin in tumor progression of human bronchopulmonary carcinomas.

The NC1 domain of alpha3 chain of type IV collagen, namely tumstatin, has been shown to display specific anti-angiogenic properties by inhibiting endothelial cells' proliferation and inducing their apoptosis via an interaction with alphavbeta3 integrin. Until now, the tumstatin anti-angiogenic effect has only been shown by in vitro studies or mouse xenograft experiments. In the present study, we examined the expression of tumstatin in relationship with tumor vascularization in 34 bronchopulmonary human carcinomas. We observed a clear association between tumstatin expression and tumor vascularization. Indeed, a strong expression of tumstatin in the tumor environment correlated with a mildly developed vascular network. In contrast, tumstatin was absent or poorly detected in highly vascularized tumors. Moreover, alphavbeta3 integrin and tumstatin colocalized in capillary endothelial cells, suggesting a potential interaction between these 2 molecules. Thus, our results plead in favor of an in vivo anti-angiogenic effect of tumstatin. This factor, largely expressed in well-differentiated lung carcinomas, could indeed reduce tumor vascularization and thereby limit tumor progression.

Recurrent human papillomavirus infection detected with the hybrid capture II assay selects women with normal cervical smears at risk for developing high grade cervical lesions: a longitudinal study of 3,091 women.

To test the reliability of the Hybrid Capture II (HC-II) assay detecting 13 high-risk human papillomavirus (HR-HPV) types for the screening of cervical lesions, we monitored by cytology, HR-HPV testing, colposcopy and biopsy, 3,091 women with normal smears at the first entry. Our primary endpoint was clinical progression defined as the presence of a high-grade lesion (HGSIL) at the biopsy. In our population of 659 HR-HPV-infected women, 241 (36.6%) had a positive HR-HPV test at 2 to 4 examinations with a final histological diagnosis of HGSIL in 51 cases (21.2%) within 4 to 36 months, while women with regressive HPV infection did not develop any lesion during the same period. In the cohort of 2,432 women testing negative for HR-HPV infection, only 2 women (0.08%) developed a HGSIL. Both were HR-HPV positive 18 and 24 months after the first entry, at the time of diagnosis of disease. The RR of incident HGSIL when a HR-HPV was detected at enrollment in women with normal smears was 96.7 (95% CI, 95.8-97.7). The RR increased to 237.3 (95% CI, 222.8-251.8) when the HR-HPV test remained positive at 2 controls, and to 314.3 (95% CI, 260.7-367.9) when the HR-HPV test was positive at 3 controls. The evaluation of the viral load of HR-HPV by the HC-II did not represent a sensitive approach to predict the recurrence of HR-HPV infection and/or the apparition of HGSIL. Nevertheless, a recurrent HR-HPV infection detected with HC-II represents a reliable tool to select populations at risk for the development of HGSIL.

Usefulness of DNA ploidy measurement on liquid-based smears showing conflicting results between cytology and high-risk human papillomavirus typing.

To improve the positive predictive value (PPV) for high-risk human papillomavirus (HR-HPV) in primary screening, DNA ploidy was measured on the same liquid-based sample by image cytometry in 984 cases showing discrepancies between cytology and HR-HPV testing. Of the conflicting results, 14.5% corresponded to a cytologic lesion (from atypical squamous cells of undetermined significance to high-grade squamous intraepithelial lesion [HSIL]) without HPV detected, and 85.5% of smears were within normal limits but revealed an HR-HPV infection. A suspect DNA profile was associated significantly with a lesion. In 497 patients who underwent repeated HPV testing, a normal DNA profile at the first smear predicted the clearance of HPV infection (sensitivity, 81.5%; specificity, 45.4%; PPV, 69%; negative predictive value, 62.4%). In persistent HR-HPV infection, a suspect DNA profile at the first smear increased the PPVfrom 10.8% to 22.7% for the detection of a histologically proven HSIL with a sensitivity of 95.2%. DNA ploidy can be used to select smears with high risk of HSIL, especially in cases of persistent HR-HPV infection.