Background-Type-1 long-QT syndrome (LQTS) is caused by loss-of-function mutations in the KCNQ1-encoded I Ks cardiac potassium channel. We evaluated the effect of location, coding type, and biophysical function of KCNQ1 mutations on the clinical phenotype of this disorder. Methods and Results-We investigated the clinical course in 600 patients with 77 different KCNQ1 mutations in 101 proband-identified families derived from the US portion of the International LQTS Registry (nϭ425), the Netherlands' LQTS Registry (nϭ93), and the Japanese LQTS Registry (nϭ82). The Cox proportional hazards survivorship model was used to evaluate the independent contribution of clinical and genetic factors to the first occurrence of time-dependent cardiac events from birth through age 40 years. The clinical characteristics, distribution of mutations, and overall outcome event rates were similar in patients enrolled from the 3 geographic regions. Biophysical function of the mutations was categorized according to dominant-negative (Ͼ50%) or haploinsufficiency (Յ50%) reduction in cardiac repolarizing I Ks potassium channel current.Patients with transmembrane versus C-terminus mutations (hazard ratio, 2.06; PϽ0.001) and those with mutations having dominant-negative versus haploinsufficiency ion channel effects (hazard ratio, 2.26; PϽ0.001) were at increased risk for cardiac events, and these genetic risks were independent of traditional clinical risk factors. Conclusions-This genotype-phenotype study indicates that in type-1 LQTS, mutations located in the transmembrane portion of the ion channel protein and the degree of ion channel dysfunction caused by the mutations are important independent risk factors influencing the clinical course of this disorder.
Purpose The panel updated the American Society of Clinical Oncology (ASCO) adjuvant therapy guideline for resected non-small-cell lung cancers. Methods ASCO convened an update panel and conducted a systematic review of the literature, investigating adjuvant therapy in resected non-small-cell lung cancers. Results The updated evidence base covered questions related to adjuvant systemic therapy and included a systematic review conducted by Cancer Care Ontario current to January 2016. A recent American Society for Radiation Oncology guideline and systematic review, previously endorsed by ASCO, was used as the basis for recommendations for adjuvant radiation therapy. An update of these systematic reviews and a search for studies related to radiation therapy found no additional randomized controlled trials. Recommendations Adjuvant cisplatin-based chemotherapy is recommended for routine use in patients with stage IIA, IIB, or IIIA disease who have undergone complete surgical resections. For individuals with stage IB, adjuvant cisplatin-based chemotherapy is not recommended for routine use. However, a postoperative multimodality evaluation, including a consultation with a medical oncologist, is recommended to assess benefits and risks of adjuvant chemotherapy for each patient. The guideline provides information on factors other than stage to consider when making a recommendation for adjuvant chemotherapy, including tumor size, histopathologic features, and genetic alterations. Adjuvant chemotherapy is not recommended for patients with stage IA disease. Adjuvant radiation therapy is not recommended for patients with resected stage I or II disease. In patients with stage IIIA N2 disease, adjuvant radiation therapy is not recommended for routine use. However, a postoperative multimodality evaluation, including a consultation with a radiation oncologist, is recommended to assess benefits and risks of adjuvant radiation therapy for each patient with N2 disease. Additional information is available at www.asco.org/lung-cancer-guidelines and www.asco.org/guidelineswiki .
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