Retrospective Analysis of Chilean and Mexican GI Stromal Tumor Registries: A Tale of Two Latin American Realities.

PURPOSE: Like other malignancies, GI stromal tumors (GIST) are highly heterogeneous. This not only applies to histologic features and malignant potential, but also to geographic incidence rates. Several studies have reported GIST incidence and prevalence in Europe and North America. In contrast, GIST incidence rates in South America are largely unknown, and only a few studies have reported GIST prevalence in Latin America. PATIENTS AND METHODS: Our study was part of a collaborative effort between Chile and Mexico, called Salud con Datos. We sought to determine GIST prevalence and patients' clinical characteristics, including survival rates, through retrospective analysis. RESULTS: Overall, 624 patients were included in our study. Our results found significant differences between Mexican and Chilean registries, such as stage at diagnosis, primary tumor location, CD117-positive immunohistochemistry status, mitotic index, and tumor size. Overall survival (OS) times for Chilean and Mexican patients with GIST were 134 and 156 months, respectively. No statistically significant differences in OS were detected by sex, age, stage at diagnosis, or recurrence status in both cohorts. As expected, patients categorized as being at high risk of recurrence displayed a trend toward poorer progression-free survival in both registries. CONCLUSION: To the best of our knowledge, this is the largest report from Latin America assessing the prevalence, clinical characteristics, postsurgery risk of recurrence, and outcomes of patients with GIST. Our data confirm surgery as the standard treatment of localized disease and confirm a poorer prognosis in patients with regional or distant disease. Finally, observed differences between registries could be a result of registration bias.

Cancer pain management: recommendations from a Latin-American experts panel.

Generating a consensus in the Latin-American region on cancer pain management is a current need. Thus a panel of Latin-American experts met in Madrid in March 2017 in order to review the published literature, discuss the best approach for cancer pain classification and evaluation and also make recommendations of pharmacological and nonpharmacological therapies for cancer pain management improvement in Latin-American countries. The result of that meeting is presented in this document. The experts participating were from Costa Rica, Mexico, Chile, Colombia, Peru, Brazil and Ecuador, and the project coordinator was from Spain.

Methylenetetrahydrofolate reductase polymorphism (677 C>T) predicts long time to progression in metastatic colon cancer treated with 5-fluorouracil and folinic acid.

BACKGROUND AND AIMS: Fluoropyrimidine-based chemotherapy is the most common treatment for unresectable metastatic colorectal cancer (m-CRC). Therapy with 5-FU/folinic acid (FA) continues to be a standard treatment in developing countries. Pharmacogenomics allows the tailoring of cancer therapy to the patient. The polymorphism 677C>T of the methylenetetrahydrofolate reductase (MTHFR) gene seems to influence the effectiveness of treatment with 5-FU. We undertook this study to evaluate the frequency of MTHFR 677C>T polymorphism and its relationship to the time to progression (TTP) and overall survival (OS) in m-CRC treated with 5-FU/FA. METHODS: The MTHFR 677C>T polymorphism was determined using PCR and allele-specific digestion. The clinical variables, TTP and OS, were analyzed in each case and compared between wild-type and variant polymorphic groups. RESULTS: Among 34 patients (12 males and 22 females), we detected eight wild-type homozygous patients (CC; 24%), nine variant homozygous (TT; 26%), and 17 heterozygous (CT; 50%) individuals. The median TTP in patients with the MTHFR 677 CC, CT, and TT genotypes was 3.43, 4.77, and 4.80 months, respectively (p = 0.047, log rank). A longer TTP was observed in patients with polymorphic variant (CT and TT) compared with the wild-type homozygous patients (4.80 vs. 3.43 months; p = 0.031, log rank). CONCLUSIONS: In this study, the frequency of the MTHFR 677C>T polymorphism is 50% among m-CRC Mexican patients. The results of this study appear to show that the presence of the MTHFR 677C>T polymorphism is associated with longer TTP and OS in m-CRC treated with 5-FU/FA.

A phase II study of gemcitabine plus cisplatin in previously untreated advanced ovarian cancer.

BACKGROUND: The primary objective was the evaluation of the effects of gemcitabine plus cisplatin on the overall response rate (ORR) of patients with advanced ovarian cancer; the secondary assessments included toxicity, time to progressive disease (TtPD) and the duration of response. MATERIALS AND METHODS: Chemonaive patients with stage III/IV ovarian cancer received gemcitabine 1250 mg/m2 (d 1,8) and cisplatin 75 mg/m2 (d 1), every 21 days for a maximum of six cycles. RESULTS: Between March 1999 and June 2003, 28 patients (median age 52 years, range 23-72) had received chemotherapy. Of 26 assessable patients, the ORR was 57.7% (95% CI, 42.7%-83.6%) based on four complete responses and eleven partial responses, six patients experienced stable disease, while five had progressive disease. The median survival was 28.1 months (95% CI, 11.4-33.4 months), the median TtPD was 10.5 months (95% CI, 1.4-44.2 months) and the median duration of response was 24.3 months (95% CI, 12.3-33.4 months). The most common grade 3/4 toxicities were nausea/vomiting (15.2%) and neutropenia (10.7%). There was no grade 3 or 4 thrombocytopenia. CONCLUSION: Gemcitabine plus cisplatin exhibited activity in advanced ovarian cancer with an acceptable toxicity profile.

Phase II study of gemcitabine plus cisplatin in metastatic breast cancer.

Our objectives were to assess the efficacy and toxicity of gemcitabine plus cisplatin as first-line therapy in metastatic breast cancer (MBC). Patients with stage IV MBC and no prior chemotherapy for metastatic disease were treated with gemcitabine 1200 mg/m on days 1 and 8, and cisplatin 75 mg/m on day 1 every 21 days. Up to 6 cycles were given. A total of 46 patients with a median age of 49 years (range 24-77) and Karnofsky performance status of 80 or above were enrolled. In total, 238 cycles were administered. Of the 42 patients evaluable for response, seven (17%) achieved a complete response and 27 (64%) a partial response, for an overall response rate of 81% [95% confidence interval (CI) 69-93%]. Median time to progression was 14.9 months (95% CI 0-30.2 months). Median duration of response was 24.2 months (95% CI 11.2-37.3 months). The median survival was 27.9 months (95% CI 23.1-32.7 months), and the 1- and 2-year survival probabilities were 71.4 and 61.4%, respectively. All patients were evaluable for toxicity, and grade 3/4 WHO toxicities included neutropenia (41.3%), anemia (8.7%), thrombocytopenia (8.7%), alopecia (26.1%) and nausea/vomiting (32.6%). We conclude that gemcitabine plus cisplatin is a highly effective and safe first-line treatment for patients with MBC. The time to progression of 14.9 months compares favorably with other standard treatments (anthracyclines, taxanes). A randomized study is required to further investigate the role of this combination as first-line treatment for MBC.

Long-term results of paclitaxel in FIGO stage III ovarian carcinoma.

The combination of platinum and paclitaxel is the standard treatment of advanced ovarian carcinoma; however, recent studies have questioned the actual role of the combination as compared to either of the two agents alone. We report an open-label, two-center, phase II study of upfront paclitaxel for patients with histological diagnosis of stage III ovarian carcinoma. Treatment consisted of paclitaxel at 175 mg/m2 administered in a 3-h infusion every 21 days. Response was evaluated after the third course by either laparoscopy or exploratory laparotomy. Patients with stable or progressive disease discontinued treatment, whereas responding patients continued treatment until a maximum of six courses. Response, toxicity, time to progression (TTP) and survival were evaluated. From November 1993 to December 1995, 30 patients were accrued. All patients underwent primary cytoreduction; 17 (57%) and 13 (43%) patients had residual tumors <2 and >2 cm, respectively. Of 27 patients evaluable, objective responses were seen in 18 (66.4%) (95% CI 49.5-83.2)--12 complete (45%) and six partial (22%). Four patients had stable disease (15%) and five (18%) patients progressed. A total of 149 courses were administered to 30 patients, median 4 (range 1-6). Grade 3/4 neutropenia was seen in 13% of courses, peripheral neuropathy, myalgia and arthralgia were frequent, but transitory and relieved with analgesics. At a median follow-up time of 44.5 months (0-99) the TTP and median survival were 16.6 and 43.1 months, respectively. We conclude that single-agent paclitaxel is an effective and well-tolerated first-line treatment for advanced ovarian carcinoma.