Merged testing for colorectal cancer syndromes and re-evaluation of genetic variants improve diagnostic yield: Results from a nationwide prospective cohort.

Approximately 5% of patients with colorectal cancer (CRC) have a Mendelian predisposition for the disease. Identification of the disease-causing genetic variant enables carrier testing and tailored cancer prevention within affected families. To determine the panorama and genetic variation of Mendelian CRC syndromes among referrals at the cancer genetics clinics in Sweden, 850 patients clinically selected for CRC genetic investigation were included in a prospective study that tested for all major hereditary polyposis and nonpolyposis CRC conditions. Genetically defined syndromes were diagnosed in 11% of the patients. Lynch syndrome was predominant (n = 73) followed by familial adenomatous polyposis (n = 12) and MUTYH-associated polyposis (n = 8); the latter of which two patients presented with CRC before polyposis was evident. One patient with a history of adolescent-onset CRC and polyposis had biallelic disease-causing variants diagnostic for constitutional mismatch repair deficiency syndrome. Post-study review of detected variants of unknown clinical significance (n = 129) resulted in the reclassification of variants as likely benign (n = 59) or as diagnostic for Lynch syndrome (n = 2). Our results reveal the panorama of Mendelian CRC syndromes at the cancer genetics clinics in Sweden and show that unified testing for polyposis and nonpolyposis CRC conditions as well as regular reexamination of sequence data improve the diagnostic yield.

A retrospective study of extracolonic, non-endometrial cancer in Swedish Lynch syndrome families.

BACKGROUND: Lynch Syndrome is an autosomal dominant cancer syndrome caused by pathogenic germ-line variants in one of the DNA-mismatch-repair (MMR) genes MLH1, MSH2, MSH6 or PMS2. Carriers are predisposed to colorectal and endometrial cancer, but also other cancer types. The purpose of this retrospective study was to characterize the tumour spectrum of the Swedish Lynch syndrome families. METHODS: Data were obtained from genetically verified 235 Lynch families from five of the six health care regions in Sweden. The material was stratified for gender, primary cancer, age and mutated gene and the relative proportions of specific cancer types were compared to those in the general population. RESULTS: A total of 1053 family members had 1493 cancer diagnoses of which 1011 were colorectal or endometrial cancer. Individuals with pathogenic variants in MLH1 and MSH2 comprised 78% of the cohort. Among the 482 non-colorectal/non-endometrial cancer diagnoses, MSH2 carriers demonstrated a significantly increased proportion of urinary tract, gastric, small bowel, ovarian and non-melanoma skin cancer compared to the normal population. MLH1 carriers had an elevated proportion of gastrointestinal cancers (gastric, small bowel, pancreas), while MSH6 carriers had more ovarian cancer than expected. Gastric cancer was predominantly noted in older generations. CONCLUSION: Lynch syndrome confers an increased risk for multiple cancers other than colorectal and endometrial cancer. The proportions of other cancers vary between different MMR genes, with highest frequency in MSH2-carriers. Gender and age also affect the tumour spectrum, demonstrating the importance of additional environmental and constitutional parameters in determining the predisposition for different cancer types.

The gynecological surveillance of women with Lynch syndrome in Sweden.

OBJECTIVE: Women with Lynch syndrome (LS) have up to a 60% lifetime risk of endometrial cancer (EC) and up to a 24% risk of ovarian cancer (OC). Gynecological surveillance is recommended, but the benefit and how it should be performed remain unclear. The purpose of this study was to assess diagnostic modalities for gynecological screening of LS patients in Sweden and clinical outcome. METHODS: A retrospective nationwide study of 170 women with molecularly confirmed LS. Data including gynecological LS screening history, biopsy results (if any), genetic records, number of screening visits, results from screening including transvaginal ultrasound (TVUS), endometrial biopsy (EB), blood test for tumor marker cancer antigen (CA) 125, prophylactic surgery including age at procedure, and setting from which screening data were obtained from medical records. RESULTS: A total of 117 women were eligible for gynecological screening and of these, 86 patients attended screening visits. Of these, 41 underwent prophylactic hysterectomy and/or bilateral salpingo-oophorectomy. Two patients (4.9%) were diagnosed with EC and two (4.9%) with precancerous lesions in conjunction with prophylactic surgery. Total incidence of gynecological cancer in the surveillance group (45 women) was 20% EC, 4% OC. Five patients had endometrial cancer or complex hyperplasia with atypia (n=2) detected by endometrial biopsy. Four additional cases were detected due to interval bleeding. Both cases of ovarian cancer were detected by transvaginal ultrasound in patients with ovarian cysts under surveillance. The youngest woman with endometrial cancer was diagnosed at 35 years of age, before she was aware of her diagnosis of Lynch syndrome. CONCLUSIONS: Gynecological surveillance of women with Lynch syndrome may lead to earlier detection of precancerous lesions, which might have some impact on the morbidity from endometrial cancer although further studies are needed to prove this. Prophylactic hysterectomy with or without bilateral salpingo-oophorectomy reduces the cancer incidence. A practical approach to surveillance in Lynch syndrome women would be to offer annual surveillance beginning at age 30 years including probably both TVUS and EB in order to increase diagnostic yield with prospective data registry for follow-up studies. Prophylactic surgery could be performed at a suitable age after childbearing to obtain a balance between reducing the risk of cancer and minimizing long-term complications from premature menopause.

Common variants of the BRCA1 wild-type allele modify the risk of breast cancer in BRCA1 mutation carriers.

Mutations in the BRCA1 gene substantially increase a woman's lifetime risk of breast cancer. However, there is great variation in this increase in risk with several genetic and non-genetic modifiers identified. The BRCA1 protein plays a central role in DNA repair, a mechanism that is particularly instrumental in safeguarding cells against tumorigenesis. We hypothesized that polymorphisms that alter the expression and/or function of BRCA1 carried on the wild-type (non-mutated) copy of the BRCA1 gene would modify the risk of breast cancer in carriers of BRCA1 mutations. A total of 9874 BRCA1 mutation carriers were available in the Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA) for haplotype analyses of BRCA1. Women carrying the rare allele of single nucleotide polymorphism rs16942 on the wild-type copy of BRCA1 were at decreased risk of breast cancer (hazard ratio 0.86, 95% confidence interval 0.77-0.95, P = 0.003). Promoter in vitro assays of the major BRCA1 haplotypes showed that common polymorphisms in the regulatory region alter its activity and that this effect may be attributed to the differential binding affinity of nuclear proteins. In conclusion, variants on the wild-type copy of BRCA1 modify risk of breast cancer among carriers of BRCA1 mutations, possibly by altering the efficiency of BRCA1 transcription.

What information do cancer genetic counselees prioritize?

This study explored the informational needs of individuals attending genetic counseling for hereditary cancer, using a free-choice and a forced choice method. Prior to the consultation the informational needs of 334 counselees from Sweden and Norway were assessed by the QUOTE-gene (ca) questionnaire and by a study specific forced choice method, using Q-methodology. Questionnaire responses indicated that counselees' major concerns pertained to the need to be taken seriously, to be provided with sufficient risk estimation and medical/genetic information and to be involved in the decision making process. Furthermore, prior to counseling, counselees noted that the counselors' consideration and skillfulness were also extremely important. Analysis of the Q-sorting results revealed that counselees' needs could be assigned to one of five groups: the "need for facts; caring communication and medical information; information and support in communicating the genetic information to others; practical care and practical/medical information". Particularly noteworthy, counselees with varying backgrounds characteristics prioritized different needs. Cancer genetic counselees probably have different needs due to their medical and demographic background when attending genetic counseling. Addressing counselees' specific concerns more sufficiently and thereby increasing the overall effectiveness of the counseling session requires increased insight into individual needs, by for instance, utilizing screening methods such as QUOTE-gene (ca) prior to the counseling session.

Bilateral prophylactic mastectomy in Swedish women at high risk of breast cancer: a national survey.

BACKGROUND/OBJECTIVE: This study attempted a national inventory of all bilateral prophylactic mastectomies performed in Sweden between 1995 and 2005 in high-risk women without a previous breast malignancy. The primary aim was to investigate the breast cancer incidence after surgery. Secondary aims were to describe the preoperative risk assessment, operation techniques, complications, histopathological findings, and regional differences. METHODS: Geneticists, oncologists and surgeons performing prophylactic breast surgery were asked to identify all women eligible for inclusion in their region. The medical records were reviewed in each region and the data were analyzed centrally. The BOADICEA risk assessment model was used to calculate the number of expected/prevented breast cancers during the follow-up period. RESULTS: A total of 223 women operated on in 8 hospitals were identified. During a mean follow-up of 6.6 years, no primary breast cancer was observed compared with 12 expected cases. However, 1 woman succumbed 9 years post mastectomy to widespread adenocarcinoma of uncertain origin. Median age at operation was 40 years. A total of 58% were BRCA1/2 mutation carriers. All but 3 women underwent breast reconstruction, 208 with implants and 12 with autologous tissue. Four small, unifocal, invasive cancers and 4 ductal carcinoma in situ were found in the mastectomy specimens. The incidence of nonbreast related complications was low (3%). Implant loss due to infection/necrosis occurred in 21 women (10%) but a majority received a new implant later. In total, 64% of the women underwent at least 1unanticipated secondary operation. CONCLUSIONS: Bilateral prophylactic mastectomy is safe and efficacious in reducing future breast cancer in asymptomatic women at high risk. Unanticipated reoperations are common. Given the small number of patients centralization seems justified.

Altered expression of cyclin E and the retinoblastoma protein influences the effect of adjuvant therapy in breast cancer.

Cyclin E and the retinoblastoma protein (Rb) are both important regulators of the G1 phase in the cell cycle. Overexpression of cyclin E and lost expression of Rb has previously been observed in breast tumours at frequencies of 10-50% and 20-30%, respectively. We explored the prognostic role of cyclin E and Rb in breast cancer patients randomised for tamoxifen (TAM), CMF (cyclophosphamide, metotrexate, 5-fluorouracil) chemotherapy and radiotherapy (RT) and how their expression affects the patients' response to treatment. Protein expression was assessed with immunohistochemistry. We found overexpression of cyclin E in 32.1% (71/221) of the tumours and loss of Rb expression in 25.0% (59/236). Increased expression of cyclin E correlated to dysfunctional p53 (P=0.003) while loss of Rb correlated to normal p53 status (P=0.001). Our results suggest that patients with high cyclin E tumours have less benefit from tamoxifen (ER+, TAM vs. no TAM; RR=0.97; 95% CI, 0.36-2.60) than patients whose tumours show low expression (ER+, TAM vs. no TAM; RR =0.41; 95% CI, 0.24-0.72). Cyclin E also tended to predict the benefit from radiotherapy with a local recurrence rate of 0.31 (RT vs. CMF; 95% CI, 0.12-0.83) for patients with low expression and 0.68 (RT vs. CMF; 95% CI, 0.2-2.32) for patients with high expression of cyclin E. When the p53 status was taken in consideration the results showed that patients with both normal p53 and normal Rb expression had considerably lower locoregional recurrence rate when treated with radiotherapy instead of CMF (RR=0.17; 95% CI, 0.052-0.58) as compared to patients with either altered Rb or p53 or both (RR=0.70; 95% CI, 0.28-1.73).

Intact Mre11/Rad50/Nbs1 complex predicts good response to radiotherapy in early breast cancer.

PURPOSE: To investigate the expression and predictive role of the Mre11/Rad50/Nbs1 (MRN) complex and the ataxia-telangiectasia mutated protein (ATM) for the outcome of radiotherapy in breast cancer patients. METHODS AND MATERIALS: The protein expression of ATM and the DNA repair proteins in the MRN complex were investigated using immunohistochemistry in tumors from 224 women with early breast cancer, who were randomized to receive postoperative radiotherapy or adjuvant chemotherapy. RESULTS: Compared with normal breast tissue, the staining intensity of Mre11, Rad50, Nbs1, and ATM was reduced in a majority of the tumors. Weak expression of the MRN complex was correlated with high histologic grade and estrogen receptor negativity (p = 0.01 and p = 0.0001, respectively). Radiotherapy significantly reduced the risk of local recurrence as compared with chemotherapy (p = 0.04). The greatest benefit of radiotherapy was seen in patients with moderate/strong expression of the MRN complex (relative risk = 0.27, 95% confidence interval = 0.098-0.72, p = 0.009), whereas patients with negative/weak MRN expression had no benefit of radiotherapy compared with adjuvant chemotherapy. These results suggest that an intact MRN complex is important for the tumor cell eradicating effect of radiotherapy. CONCLUSIONS: Reduced expression of the MRN complex predicts a poor effect of radiotherapy in patients with early breast cancer.

The BRCA1/BRCA2/Rad51 complex is a prognostic and predictive factor in early breast cancer.

BACKGROUND AND PURPOSE: The breast cancer susceptibility genes BRCA1 and BRCA2 interact with Rad51, one of the central components in the homologous recombination repair pathway. This study evaluates the prognostic and predictive role of BRCA1, BRCA2 and Rad51, individually and as a complex, in breast cancer. MATERIALS AND METHODS: Expression of BRCA1, BRCA2 and Rad51 was investigated using immunohistochemistry in tumours from 224 women with early breast cancer, who were randomised to receive postoperative radiotherapy or adjuvant chemotherapy (CMF). RESULTS: Fifty-three percent (112/212) of the tumours had reduced expression of the BRCA1/BRCA2/Rad51 complex. Low expression correlated to high histologic grade (p=0.05). Patients with low expression of the complex developed significantly more local recurrences as compared to patients with high expression (RR=3.20, 95% CI 1.48-6.88, p=0.003). Expression of the BRCA1/BRCA2/Rad51 complex was an independent prognostic factor in multivariate analysis (p=0.03). Patients with low expression of the complex responded well to radiotherapy (RR=0.31, 95% CI 0.14-0.70, p=0.005), whereas patients with high expression had few local recurrences and no additional benefit from radiotherapy (RR=1.08, 95% CI 0.40-2.90, p=0.88). CONCLUSIONS: Low expression of the BRCA1/BRCA2/Rad51 complex is a marker of poor prognosis, but predicts good response to radiotherapy in patients with early breast cancer.

Low expression of Ku70/80, but high expression of DNA-PKcs, predict good response to radiotherapy in early breast cancer.

The purpose was to study the prognostic and predictive roles of DNA protein kinase catalytic subunit (DNA-PKcs), Ku70/80 and p53 for the effect of radiotherapy in breast cancer patients. Protein expressions of Ku70/80, DNA-PKcs and p53 were examined using immunohistochemistry in tumours from 224 breast cancer patients, who were randomised to receive post-operative radiotherapy or adjuvant chemotherapy (cyclophosphamide, methotrexate, 5-fluorouracil). One hundred and twenty-nine (60%) of the tumours had low expression of Ku70/80, 122 (57%) had low expression of DNA-PKcs and 65 (30%) had altered p53 expression. None of the proteins were indicative to the prognosis of local recurrence-free survival. Even though the expression of Ku70/80 and DNA-PKcs correlated well, they were not associated with treatment outcome in the same way. Low expression of Ku70/80 predicted good effect of radiotherapy (RR=0.31, 95% CI 0.13-0.76, p=0.01). In contrast, the greatest benefit of radiotherapy over chemotherapy was seen in patients with high DNA-PKcs expression (RR=0.25, 95% CI 0.07-0.84, p=0.02). Altered p53 expression predicted poor response to radiotherapy. We believe that the results reflect the different roles of DNA-PKcs and Ku70/80 in repair and cell death regulation after DNA damage. These differences could be of importance when developing drugs that target DNA repair.

p53 polymorphic variants at codon 72 and the outcome of therapy in randomized breast cancer patients.

BACKGROUND: Adjuvant therapy of breast cancer patients reduces the risk of recurrence and mortality, although, a substantial proportion of patients acquire resistance and relapse in the disease. Predictors of therapeutic response are therefore important to avoid both therapy resistance and the side effects of inefficient regimes. The p53 protein is a key determinant to induce either growth arrest or apoptosis in response to cytotoxic stress. METHODS: In the search for predictive markers of cancer therapy we investigated a common Arg72/Pro72 polymorphism in the p53 gene, which has been shown to influence the apoptotic potential. Using PCR and RFLP we genotyped 220 breast cancer patients randomized to radiotherapy versus chemotherapy and tamoxifen versus no tamoxifen. RESULTS: Oestrogen-receptor positive patients possessing at least one Pro72 allele had better distant recurrence-free survival when randomized to tamoxifen compared to those who were not (P=0.0033), as also demonstrated by the significantly decreased hazard ratio (HR=0.28, 95% CI 0.12-0.65). Among patients homozygous for the Arg72 genotype the outcome was approximately equal between tamoxifen treated and non-tamoxifen treated patients (P=0.65). When the calculated hazard ratios for the genotypes were compared by an interaction test a significant difference was found (P=0.0088). CONCLUSION: The present report indicates that the codon 72 polymorphism in the p53 gene may be a predictor of tamoxifen response, suggesting that breast cancer patients lacking the Pro72 allele might be candidates for other therapies.

Mutation and accumulation of p53 related to results of adjuvant therapy of postmenopausal breast cancer patients.

p53 protein accumulation and gene mutation have been implicated in resistance to cytotoxic treatment. This study was performed to further assess the predictive value of p53 in breast cancer. Postmenopausal patients were randomized to adjuvant chemotherapy with cyclophosphamide, metothrexate, or 5-fluorouracil (CMF) vs. postoperative radiotherapy. The patients were also randomized to adjuvant tamoxifen vs. no endocrine treatment. Immunohistochemistry (IHC) and single-strand conformation polymorphism (SSCP), followed by direct sequencing, was performed. The p53 altered group, regarded as positive for p53 gene mutation and/or p53 protein accumulation, tended to benefit more from CMF than from radiotherapy as compared with others regarding distant recurrences. In the group lacking p53 alteration there was a significantly decreased local recurrence rate in the radiotherapy group as compared with the CMF group (RR = 0.24, 95% CI = 0.083 0.62), whereas no benefit from radiotherapy was found for patients showing p53 alterations. Tamoxifen significantly decreased the rate of distant recurrence for estrogen receptor-positive patients with no apparent difference in relation to p53 alteration. It is suggested that p53 alteration indicates benefit from CMF compared with radiotherapy regarding distant recurrence-free survival and the best local control with radiotherapy is achieved in the absence of p53 alteration. Finally, altered p53 status is probably not a marker of resistance to tamoxifen.