Pacini F, Elisei R, Anelli S, Basolo F, Cola A, Pinchera A
Cattedra di Endocrinologia, Università di Pisa, Italy.
Cancer. 1989 Mar 15;63(6):1189-95. doi: 10.1002/1097-0142(19890315)63:6<1189::aid-cncr2820630625>3.0.co;2-j.
The authors evaluated the presence of somatostatin (SRIF) in the plasma and in the tumor tissue of a total of 22 patients with medullary thyroid cancer (MTC) and studied the effect of exogenous SRIF administration on basal and pentagastrin (PG)-stimulated plasma calcitonin (CT) and carcinoembryonic antigen (CEA) levels. Mean plasma SRIF concentrations were significantly higher than those found in normal controls, with five of 15 patients having plasma SRIF levels above the mean + 2 SD of normal controls. High immunoreactive SRIF concentrations were found in the extract of three tumor tissues but not in one follicular thyroid cancer or in one toxic diffuse goiter. By immunoperoxidase staining seven of 11 (63.6%) primary MTC and five of 13 (38.5%) metastases expressed SRIF antigen in a low number of cells and with a weak degree of staining. As expected, CT was expressed in almost 100% of the cases with positivity in most of the cells and strong degree of staining. Patients with positive SRIF staining in the primary tumor had longer survival than SRIF negative patients. Infusion of synthetic SRIF (11 micrograms/minute/45 minutes) produced a significant reduction of plasma CT (but not CEA) levels in 12 of the 15 patients submitted to this test. Maximal percent decrease of plasma CT ranged from 10.8% to 72.7% of the basal value and was usually observed between 30 and 45 minutes from the beginning of the infusion. When infused together with the injection of PG, SRIF was able to significantly (P less than 0.05) inhibit the PG-induced CT release in five of six patients tested. These results demonstrate the following: SRIF is present in a few cells of many primary MTC and less frequently in their metastases; tentatively, the expression of SRIF antigen in the tumor seems to be associated with longer survival; increased SRIF concentrations are found in the plasma of some patients with metastatic involvement; and treatment with exogenous SRIF reduces the basal and PG-induced CT (but not CEA) release from the tumor.
作者评估了22例甲状腺髓样癌（MTC）患者血浆和肿瘤组织中生长抑素（SRIF）的存在情况，并研究了外源性SRIF给药对基础状态及五肽胃泌素（PG）刺激后的血浆降钙素（CT）和癌胚抗原（CEA）水平的影响。MTC患者的血浆SRIF平均浓度显著高于正常对照，15例患者中有5例血浆SRIF水平高于正常对照均值+2个标准差。在3例肿瘤组织提取物中发现高免疫反应性SRIF浓度，但在1例滤泡状甲状腺癌和1例毒性弥漫性甲状腺肿中未发现。通过免疫过氧化物酶染色，11例原发性MTC中有7例（63.6%）、13例转移灶中有5例（38.5%）在少量细胞中表达SRIF抗原，染色程度较弱。正如预期的那样，几乎100%的病例中CT呈阳性表达，大多数细胞呈阳性且染色程度较强。原发性肿瘤中SRIF染色阳性的患者比SRIF阴性患者生存期更长。对15例接受该试验的患者中的12例输注合成SRIF（11微克/分钟/45分钟）后，血浆CT水平显著降低（但CEA水平未降低）。血浆CT的最大降幅为基础值的10.8%至72.7%，通常在输注开始后30至45分钟观察到。当与PG注射同时输注时，SRIF能够在6例受试患者中的5例中显著（P<0.05）抑制PG诱导的CT释放。这些结果表明：SRIF存在于许多原发性MTC的少数细胞中，在转移灶中出现的频率较低；初步认为，肿瘤中SRIF抗原的表达似乎与较长生存期相关；一些有转移的患者血浆中SRIF浓度升高；外源性SRIF治疗可降低肿瘤基础状态及PG诱导的CT（但不包括CEA）释放。
