KRAS and BRAF mutations and MSI status in precursor lesions of colorectal cancer detected by colonoscopy

Colorectal cancer (CRC) is one of the most frequent cancers worldwide. Adenoma is the main precursor lesion and, recently, the serrated polyps were described as a group of colorectal lesions with malignant potential. The morphologic and biologic characterizations of serrated polyps remain limited. The aim of the present study was to determine the frequency of KRAS and BRAF mutations and microsatellite instability (MSI) in CRC precursor lesions, to evaluate the association between molecular, pathologic and morphologic alterations in precursor lesions and to compare with the alterations detected in CRC. A series of 342 precursor lesions were removed from 155 patients during colonoscopy. After morphologic classification, molecular analysis was performed in 103 precursor lesions, and their genetic profile compared with 47 sporadic CRCs. Adenomas were the main precursor lesions (70.2%). Among the serrated polyps, the main precursor lesion was hyperplastic polyps (HPs) (82.4%), followed by sessile serrated adenomas (12.7%) and traditional serrated adenomas (2.0%). KRAS mutations were detected in 13.6% of the precursor lesions, namely in adenomas and in HPs, but in no serrated adenoma. BRAF mutations were found in 9 (8.7%) precursor lesions, mainly associated with serrated polyps and absent in adenomas (P<0.001). High MSI (MSI-H) was absent in precursor lesions. In the 47 CCR cases, 46.8% exhibited KRAS mutation, 6.5% BRAF mutations and 10.6% MSI-H. This study confirms the role of KRAS and BRAF mutations in CRC carcinogenesis, a crucial step in implementing CRC screening strategies.

SOD2 immunoexpression predicts lymph node metastasis in penile cancer

BACKGROUND

Superoxide dismutase-2 (SOD2) is considered one of the most important antioxidant enzymes that regulate cellular redox state in normal and tumorigenic cells. Overexpression of this enzyme in lung, gastric, colorectal, breast cancer and cervical cancer malignant tumors has been observed. Its relationship with inguinal lymph node metastasis in penile cancer is unknown.

METHODS

SOD2 protein expression levels were determined by immunohistochemistry in 125 usual type squamous cell carcinomas of the penis from a Brazilian cancer center. The casuistic has been characterized by means of descriptive statistics. An exploratory logistic regression has been proposed to evaluate the independent predictive factors of lymph node metastasis.

RESULTS

SOD2 expression in more than 50% of cells was observed in 44.8% of primary penile carcinomas of the usual type. This expression pattern was associated with lymph node metastasis both in the uni and multivariate analysis.

CONCLUSIONS

Our results indicate that SOD2 expression predicts regional lymph node metastasis. The potential clinical implication of this observation warrants further studies.

Evaluation of human papillomavirus self-collection offered by community health workers at home visits among under-screened women in Brazil

OBJECTIVE

To explore the acceptability of high-risk human papillomavirus self-testing, involving community health workers, for never/under-screened Brazilian women. Cervical cancer is the most common cause of cancer-related death among adult women in a large number of low-income and lower-middle-income countries, where it remains a major public health problem. High-risk human papillomavirus persistence is required for the development of cervical neoplasia.

METHODS

The target population was all women aged 30+ from the list of families available in healthcare centre data, who had never been screened or were not screened in the previous 3 years (under-screened women), and who were living in the 17 cities included in this study.

RESULTS

Of the 377 women included, 16.9% (n = 64) had never had a pap smear. Of all samples included in the study, 97.1% (n = 366) were considered adequate for evaluation, as 2.9% (n = 11) were considered invalid for all high-risk human papillomavirus types. Analysing these 366 samples, 9.6% (n = 35) of the women were infected by at least one high-risk human papillomavirus type and 90.4% (n = 331) had no infection with any high-risk type of the virus.

CONCLUSIONS

Vaginal self-sampling is an adequate strategy to improve the effectiveness of the cervical cancer program by increasing screening in a high-risk group.

Evaluation of estrogen receptor alpha, estrogen receptor beta, progesterone receptor, and cKIT expression in desmoids tumors and their role in determining treatment options

The present study evaluates the protein expression of estrogen receptor alpha (ERalpha), estrogen receptor beta (ERbeta), progesterone receptor (PR) and cKIT in a wide number of desmoids tumors and their role in determining treatment options. Fifty-nine cases classified as muscle aponeurotic fibromatosis were selected. Samples were grouped by tumor location in: head and neck, extremity and abdominal/trunk; type of resection of the primary tumor (complete resection with adequate margins, marginal resection and resection with inadequate margins); type of treatment (exclusive surgery, surgery followed by radiation therapy and surgery followed by tamoxifen or cyclooxygenase inhibitor). A tissue microarray (TMA) was built and the immunohistochemical reactions were performed against ERalpha, ERbeta, PR, and c-kit. All cases were negative for ERalpha, PR and c-KIT. 53/59 cases were positive for ERbeta. No significant difference was observed among clinical variables and the ERbeta status. The estimated 5 and 10 year local recurrence free survival (LRFS) for the patients with complete or marginal resection was 75% and 75%, respectively. Tumor location (p = 0.006) and type of resection (p = 0.001) were predictive of local relapse in the univariate analysis. All patients treated with post-operative tamoxifen were LRFS (p = 0.035). Head and neck and extremities lesions showed higher recurrence rates compared to abdominal/trunk lesions. Marginal resection was associated with local recurrence. In conclusion, although this is a retrospective study, the results presented can contribute to better understanding of the mechanisms under desmoid tumor development and can propose tamoxifen as a therapeutic option to be tested in prospective trials.