Treatment progress of non-small cell lung cancer with RET gene fusion / 肿瘤研究与临床

Non-small cell lung cancer (NSCLC) is a malignant tumor with rapid progress and high malignancy, accounting for 85% of all lung cancers. Treatment has shifted from traditional surgery, radiotherapy and chemotherapy to targeted therapy. Targeted therapy can prolong the survival of patients with positive driver gene fusion. With the continuous progress of biological research, targets related to NSCLC have gradually been discovered. Among the many driving genes of NSCLC, RET fusion is an important emerging target discovered in recent years. It has been confirmed to have a high incidence in non-smoking, young and low-differentiated NSCLC patients. This article reviews RET gene fusion in NSCLC, the relationship between the two and the treatment progress.

Surgical approach to medullary thyroid cancer

Medullary thyroid cancer (MTC) compromises 3-5 percent of all thyroid cancers and arises from parafollicular or calcitonin-producing C cells. It may be sporadic (75 percent of cases), or may occur as a manifestation of either the hereditary syndrome Multiple Endocrine Neoplasia type 2 (MEN 2A or MEN 2B) (25 percent of cases), or rarely as an isolated familial syndrome (FMTC). Complete surgical resection comprising in most cases total thyroidectomy with central lymph node dissection at an early stage of the disease is the only potential cure for MTC. The familial form of the disease, MEN-2A occupies a unique place in surgical history, having been the first disease where surgical removal of an affected organ was undertaken before the development of malignancy, solely on the basis of genetic testing. Total thyroidectomy prior to the development of invasive cancer completely avoids an otherwise lethal malignancy. Timing of prophylactic surgery is based on models that utilise genotype-phenotype correlations, which have now been stratified into three risk groups based on the specific codon involved. MTC should be followed with postoperative serial serum calcitonin levels to survey for persistent or recurrent disease as indicated by detectable levels. The challenge however, if calcitonin levels are increased, is to find the source of its production. The first localisation technique recommended would be ultrasound of the neck, since there is a high frequency of local recurrence and cervical node metastasis, followed by a total body CT scan and bone scintigraphy.

O carcinoma medular de tiróide (CMT) abrange 3-5 por cento do câncer de tiróide em geral e surge da célula parafolicular ou célula C produtora de calcitonina. Pode ser esporádico (75 por cento dos casos), ou pode ocorrer como uma das manifestações das síndromes hereditárias Neoplasia Endócrina Múltipla tipo 2 (NEM2A ou NEM2B) (25 por cento dos casos), ou mais raramente como uma síndrome familiar isolada (CMTF). A ressecção cirúrgica completa, que na maioria dos casos consiste de tireoidectomia total com dissecção dos linfonodos nos estágios precoces da doença, é a única forma de cura potencial de CMT. A forma de doença familiar da patologia NEM2A ocupa um lugar único na história da cirurgia, tendo sido a primeira doença onde a remoção cirúrgica de um órgão afetado foi realizada antes do desenvolvimento da malignidade, baseado somente no teste genético. A tireoidectomia total antes do desenvolvimento do câncer invasivo evita de outra forma a malignidade letal. A época da cirurgia profilática está baseada nos modelos que utilizam a correlação genótipo-fenótipo, que atualmente está estratificada em três grupos de risco baseado no códon envolvido. O CMT deve ser acompanhado após a cirurgia com dosagem de calcitonina sérica, cujo nível, quando detectável, indicaria a persistência ou recorrência da doença. O desafio, no entanto, se os níveis de calcitonina estão elevados, é encontrar a fonte desta produção. A primeira técnica de localização recomendada seria o ultrassom do pescoço, já que ocorre uma alta freqüência de recorrência local e de metástase dos nódulos cervicais, seguida de tomografia computadorizada do corpo inteiro e de cintilografia óssea.

Ret rearrangement mutation in patients with papillary thyroid carcinoma / 中华内分泌代谢杂志

Objective To investigate the association of ret gene rearrangement mutation with the pathogenesis of papillary thyroid carcinoma (PTC). Methods Twenty-seven cases of PTC were analysed for expression of ret gene rearrangement (ret/PTCs) by multiplex-PCR at first, and then ret/PTC1-3 were identified by identification-PCR (ID-PCR). Finally, the specific ret/PTC was affirmed by automated direct sequencing. Ten specimens of malignant thyroid tissues of other histological types, 33 benign thyroid lesions and 30 normal thyroid specimens beside tumor (as the control) were also included. Results (1) Fifteen samples showed positive ret/PTCs, 11 of which harboured ret/PTC1,3 were positive for ret/PTC3, and 1 for ret/PTC2. All the rearrangements were clearly identified by automated direct sequencing of ID-PCR products. (2) All the 15 ret/PTC-positive tissue samples were histologically confirmed to be PTC. The prevalence of the tumor-specific ret rearrangements in 27 patients with PTC is 55.6% (15/27). (3) No significant difference was found regarding the gender and age of the patients, tumor size and metastasis of neck lymph node. 33.3% (2/6) of the PTC with invasion of extrathyroidal soft tissue were ret/PTC-positive, as compared with 66.7%(4/6) for ret/PTC-negative group (P