All the children registered at the National Council for the Prevention and Treatment of Childhood Cancer were analyzed. The rationale for this Federal Government Council is to financially support the treatment of all children registered into this system. All patients are within a network of 55 public certified hospitals nationwide. In the current study, data from 2007 to 2012 are presented for all patients (0–18 years) with a pathological diagnosis of leukemia, lymphoma and solid tumors. The parameters analyzed were prevalence, incidence, mortality, and abandonment rate. A diagnosis of cancer was documented in 14,178 children. The incidence was of 156.9/million/year (2012). The median age was 4.9. The most common childhood cancer is leukemia, which occurs in 49.8% of patients (2007–2012); and has an incidence rate of 78.1/million/year (2012). The national mortality rate was 5.3/100,000 in 2012, however in the group between 15 to 18 years it reaches a level of 8.6. The study demonstrates that there is a high incidence of childhood cancer in Mexico. In particular, the results reveal an elevated incidence and prevalence of leukemia especially from 0 to 4 years. Only 4.7% of these patients abandoned treatment. The clinical outcome for all of the children studied improved since the establishment of this national program.
Intratumoral expression of genes encoding Cytochrome P450 enzymes (CYP) might play a critical role not only in cancer development but also in the metabolism of anticancer drugs. The purpose of this study was to compare the mRNA expression patterns of seven representative CYPs in paired tumor and normal tissue of child patients with rabdomyosarcoma (RMS). Using real time quantitative RT-PCR, the gene expression pattern of CYP1A1, CYP1A2, CYP1B1, CYP2E1, CYP2W1, CYP3A4, and CYP3A5 were analyzed in tumor and adjacent non-tumor tissues from 13 child RMS patients. Protein concentration of CYPs was determined using Western blot. The expression levels were tested for correlation with the clinical and pathological data of the patients. Our data showed that the expression levels of CYP1A1 and CYP1A2 were negligible. Elevated expression of CYP1B1 mRNA and protein was detected in most RMS tumors and adjacent normal tissues. Most cancerous samples exhibit higher levels of both CYP3A4 and CYP3A5 compared with normal tissue samples. Expression of CYP2E1 mRNA was found to be significantly higher in tumor tissue, however no relation was found with protein levels. CYP2W1 mRNA and/or protein are mainly expressed in tumors. In conclusion, we defined the CYP gene expression profile in tumor and paired normal tissue of child patients with RMS. The overexpression of CYP2W1, CYP3A4 and CYP3A5 in tumor tissues suggests that they may be involved in RMS chemoresistance; furthermore, they may be exploited for the localized activation of anticancer prodrugs.
Limited data describe the delivery of pediatric cancer care in Mexico. We report a nationwide survey of pediatric cancer units. An electronic survey was distributed to 74 pediatric cancer units in Mexico to describe case volumes; organization of care; and availability of medical/surgical specialists, supportive care, complex therapies, and diagnostic services. Centers were classified as low (< 30 new patients/year), medium (30 to 59/year) and high (≥ 60/year). Sixty-two centers completed the survey (response rate, 84%). The median annual new case volume per center was 50 (interquartile range [IQR], 23 to 81). Thirty-four percent (n = 21), 26% (n = 16), and 40% (n = 25) of units were low-, medium-, and high-volume centers, respectively. Treatment units reported a median of two pediatric oncologists (IQR, 2) and one pediatric hematologist (IQR, 1 to 2). Availability of medical and surgical subspecialists varied by center size, with substantially more specialist support at higher-volume centers (P < .01). Multidisciplinary tumor boards are available at 29% (six of 21), 56% (nine of 16), and 76% (19 of 25) of low- to high-volume centers, respectively (P = .005). Radiation and palliative care services are available at 42% (n = 26) and 63% (n = 36) of all centers, which did not vary by center volume. Educational support for hospitalized children and school reintegration programs are available at 56% (n = 36) and 58% (n = 36) of centers, respectively. One third (38% [n = 23]) of centers reported that at least one half of patients were lost to follow-up during the transition from pediatric to adult programs. A large variation exists in annual case volumes across Mexican pediatric cancer centers. Additional efforts to increase access to multidisciplinary, supportive, and palliative care across all pediatric cancer units in Mexico are required.