Cultivable Microbiome Approach Applied to Cervical Cancer Exploration.

Traditional microbiological methodology is valuable and essential for microbiota composition description and microbe role assignations at different anatomical sites, including cervical and vaginal tissues; that, combined with molecular biology strategies and modern identification approaches, could give a better perspective of the microbiome under different circumstances. This pilot work aimed to describe the differences in microbiota composition in non-cancer women and women with cervical cancer through a culturomics approach combining culture techniques with Vitek mass spectrometry and 16S rDNA sequencing. To determine the possible differences, diverse statistical, diversity, and multivariate analyses were applied; the results indicated a different microbiota composition between non-cancer women and cervical cancer patients. The Firmicutes phylum dominated the non-cancer (NC) group, whereas the cervical cancer (CC) group was characterized by the predominance of Firmicutes and Proteobacteria phyla; there was a depletion of lactic acid bacteria, an increase in the diversity of anaerobes, and opportunistic and non-typical human microbiota isolates were present. In this context, we hypothesize and propose a model in which microbial composition and dynamics may be essential for maintaining the balance in the cervical microenvironment or can be pro-oncogenesis microenvironmental mediators in a process called Ying-Yang or have a protagonist/antagonist microbiota role.

Radiation oncology in Mexico: Current status according to Mexico's Radiation Oncology Certification Board.

AIM: Describe the results of the first national census of radiotherapy in Mexico in order to make a situational diagnosis of radiotherapy availability, offer more accurate information to radiation oncologists, and promote an adequate scientific based investment for the country. BACKGROUND: According to the Organisation for Economic Co-operation and Development (OECD), the density of radiotherapy (RT) machines per million habitants in Mexico is approximately 1.7-1.8. Other international organizations such as DIRAC-IAEA report 1.15 per million habitants. National organizations collect data indirectly and previous surveys had a low accrual rate (32.5%). Therefore, a precise census is required. MATERIAL AND METHODS: The Mexican Radiation Oncology Certification Board (CMRO for its acronym in Spanish) conducted a nationwide census from January through November 2019. Gathered information was combined with CMRO database for sociodemographic information and human resources. RESULTS: The study included 103 RT centers [95.1% answered the survey], with a median of 2 centers by state (ranging from 0 in Tlaxcala to 20 in Mexico City) and with a report of only 1 center in 11 states (34.4%). Fifty-six (54.3%) of the centers are public. Fourteen centers (13.6%) have residency-training programs. The total number of RT machines is 162 [141 clinical and linear accelerators (87%) and 21 radionuclide units (13%)] with a median of 3 machines by state (0 in Tlaxcala to 46 in Mexico City) and with ≤3 machines in 18 states (56.25%). The overall calculated density of RT machines per million habitants is 1.32, varying from 0 in Tlaxcala to 5.16 in Mexico City. The density of linear and clinical accelerators per million population is 1.19. The total number of brachytherapy units is 66, with a median of 1 center with brachytherapy unit per state and 29 states with ≤3 centers with a brachytherapy unit (90.6%). Thirty-seven brachytherapy units (56.1%) have automated afterload high-dose rate. The overall rate of brachytherapy units per million inhabitants is 0.55, varying from 0 in 5 states (15.6%), 0.1-0.49 in 8 states (25%), 0.5-0.99 in 13 states (40.6%), 1-1.49 in 5 states (15.6%) and 1.5-1.99 in Mexico City (3.1%). The Mexican CMRO has 368 radiation oncologists certified (99 women and 269 men), of whom only 346 remain as an active part of Mexico's workforce. CONCLUSIONS: This is the first time the CMRO conducts a national census for a radiotherapy diagnostic situation in Mexico. The country currently holds a density of clinical and linear accelerators of 1.19 per million habitants. Brachytherapy density is 0.55 devices per million habitants, and 57% of radiotherapy centers have brachytherapy units.

Biochemical relapse free survival rate in patients with prostate cancer treated with external radiotherapy: outcomes obtained at the CMN Siglo XXI Hospital de Oncología, CMN 20 de Noviembre and Hospital General de México of the México City.

AIM: Biochemical relapse-free survival (bRFS) rate is determined by a cohort of Mexican patients (n = 595) with prostate cancer who received treatment with external radiotherapy. BACKGROUND: Patients with prostate cancer were collected from CMN Siglo XXI (IMSS), CMN 20 de Noviembre (ISSSTE), and Hospital General de México (HGM). For the IMSS, 173 patients that are treated with three-dimensional conformal radiation therapy (3D-CRT) and 250 with SBRT, for the ISSSTE 57 patients are treated with 3D-CRT and on the HGM 115 patients are managed with intensity modulated radiation therapy (IMRT). The percentage of patients by risk group is: low 11.1%, intermediate 35.1% and high 53.8%. The average follow-up is 39 months, and the Phoenix criterion was used to determine the bRFS. MATERIALS AND METHODS: The Kaplan-Meier technique for the construction of the survival curves and, the Cox proportional hazards to model the cofactors. RESULTS: (a) The bRFS rates obtained are 95.9% for the SBRT (7 Gy fx, IMSS), 94.6% for the 3D-CRT (1.8 Gy fx, IMSS), 91.3% to the 3D-CRT (2.65 Gy fx, IMSS), 89.1% for the SBRT (7.25 Gy fx, IMSS), 88.7% for the IMRT (1.8 Gy fx, HGM) %, and 87.7% for the 3D-CRT (1.8 Gy fx, ISSSTE). (b) There is no statistically significant difference in the bRFS rates by fractionation scheme, c) Although the numerical difference in the bRFS rate per risk group is 95.5%, 93.8% and 89.1% for low, intermediate and high risk, respectively, these are not statistically significant. CONCLUSIONS: The RT techniques for the treatment of PCa are statistically equivalent with respect to the bRFS rate. This paper confirms that the bRFS rates of Mexican PCa patients who were treated with conventional vs. hypofractionated schemes do not differ significantly.

Hypofractionation with concomitant boost using intensity-modulated radiation therapy in early-stage breast cancer in Mexico.

AIM: To evaluate whether hypofractionation with integrated boost to the tumour bed using intensity-modulated radiation therapy is an acceptable option and to determine whether this treatment compromises local control, toxicity and cosmesis. BACKGROUND: Retrospective studies have demonstrated that patients who are treated with HF and integrated boost experience adequate local control, a dosimetric benefit, decreased toxicity and acceptable cosmesis compared with conventional fractionation. MATERIALS AND METHODS: A retrospective, observational and longitudinal study was conducted from January 2008 to June 2015 and included 34 patients with breast cancer (stage 0-II) who were undergoing conservative surgery.The prescribed doses were 45 Gy in 20 fractions (2.25 Gy/fraction) to the breast and 56 Gy in 20 fractions (2.8 Gy/fraction) to the tumour bed. RESULTS: Thirty-four patients were included. The mean follow-up was 49.29 months, and the mean age was 52 years. The mean percentage of PTV from the mammary region that received 100% of the prescribed dose was 97.89% (range 95-100), and the mean PTV percentage of the tumour bed that received 100% of the dose was 98% (95-100).The local control and the overall survival were 100%, and the cosmesis was good in 82% of the patients. Grade 1 acute toxicity was present in 16 patients (47%), and grade 1 chronic toxicity occurred in 6 cases (18%). CONCLUSION: The results of the present study demonstrate that hypofractionation with integrated boost using intensity-modulated radiation therapy is an acceptable option that provides excellent local control and low toxicity.

[Surgical-pathologic correlation to assess the margin status in wide local excision for early-stages breast cancer]. / Correlación quirúrgico-patológica para evaluar el estado de los bordes en las escisiones locales amplias de cáncer mamario en etapas clínicas tempranas.

OBJETIVE: To know the surgical-pathologic correlation to assess the state of the edges in wide local excisions of breast cancer in clinical stages. MATERIAL AND METHODS: retrospective and descriptive study, conducted in Breast Tumors Unit from Oncology Service of the General Hospital of Mexico, in the period from January 2009 to December 2011, with follow-up in December2012. Were included patients with breast cancer in early clinical stages, subject wide local excisions histopalogic report of a second surgery. RESULTS: From wide local excisions, 119 (28.5%) were due to breast cancer and included. Positive margins after initial surgery were diagnosed in 63 patients (52.9%). The residual tumor found in the second surgery was 39.7%. The variables associated with the presence of positive margins and statistically significant (p≤ 0.05) were: multicentricity, tumor size clinical and pathological, histological subtypes, and tumor grade. The age and clinical stage were not statistically significant. The variables associated with the presence of residual tumor and are statistical relevance (p≤ 0.05) were clinical stage, tumor size, clinical and pathological, histological variant and histological grade. Age and multicentricity were not associated with the presence of residual tumor. CONCLUSION: Although each case must be individualized, these results demonstrate the analyzed factors must be taken into account during the planning of breast conservative procedures, and despite an histopalogical report of margin after an initial surgery, even seconds procedures can be performed to conserve the organ.