International Society of Paediatric Oncology (SIOP) Global Mapping Programme: Latin American Society of Pediatric Oncology (SLAOP) country-level report

BACKGROUND

Latin American countries are improving childhood cancer care, showing strong commitment to implement the Global Initiative for Childhood Cancer, but there are scant publications of the situation at a continental level.

METHODS

As part of the International Society of Paediatric Oncology Global Mapping project, delegates of each country participating in the Latin American Society of Pediatric Oncology (SLAOP) and chairs of national pediatric oncology societies and cooperative groups were invited to provide information regarding availability of national pediatric cancer control programs (NPCCP), pediatric oncology laws, pediatric oncology tumor registries, and training programs and support to diagnosis and treatment.

RESULTS

Nineteen of the 20 countries participating in SLAOP responded. National delegates reported nine countries with NPCCP and four of them were launched in the past 5 years. National pediatric tumor registries are available in eight countries, and three provided published survival results. Fellowship programs for training pediatric oncologists are available in 12 countries. National delegates reported that eight countries provide support to most essential diagnosis and treatments and 11 provide partial or minimal support that is supplemented by civil society organizations. Seven countries have a pediatric oncology law. There are three international cooperative groups and four national societies for pediatric oncology.

CONCLUSION

Despite many challenges, there were dramatic advances in survivorship, access to treatment, and availability of NPCCP in Latin America. Countries with highest social development scores in general provide more complete support and are more likely to have NPCCP, training programs, and reported survival results.

Delivery of Pediatric Cancer Care in Mexico: A National Survey

Purpose Limited data describe the delivery of pediatric cancer care in Mexico. We report a nationwide survey of pediatric cancer units. Methods 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). Results 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. Conclusion 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.

Cervical cancer cell lines expressing NKG2D-ligands are able to down-modulate the NKG2D receptor on NKL cells with functional implications

BACKGROUND

Cervical cancer represents the third most commonly diagnosed cancer and the fourth leading cause of cancer-related deaths in women worldwide. Natural killer (NK) cells play an important role in the defense against viruses, intracellular bacteria and tumors. NKG2D, an activating receptor on NK cells, recognizes MHC class I chain-related molecules, such as MICA/B and members of the ULBP/RAET1 family. Tumor-derived soluble NKG2D-ligands have been shown to down-modulate the expression of NKG2D on NK cells. In addition to the down-modulation induced by soluble NKG2D-ligands, it has recently been described that persistent cell-cell contact can also down-modulate NKG2D expression. The goal of this study was to determine whether the NKG2D receptor is down-modulated by cell-cell contact with cervical cancer cells and whether this down-modulation might be associated with changes in NK cell activity.

RESULTS

We demonstrate that NKG2D expressed on NKL cells is down-modulated by direct cell contact with cervical cancer cell lines HeLa, SiHa, and C33A, but not with non-tumorigenic keratinocytes (HaCaT). Moreover, this down-modulation had functional implications. We found expression of NKG2D-ligands in all cervical cancer cell lines, but the patterns of ligand distribution were different in each cell line. Cervical cancer cell lines co-cultured with NKL cells or fresh NK cells induced a marked diminution of NKG2D expression on NKL cells. Additionally, the cytotoxic activity of NKL cells against K562 targets was compromised after co-culture with HeLa and SiHa cells, while co-culture with C33A increased the cytotoxic activity of the NKL cells.

CONCLUSIONS

Our results suggest that differential expression of NKG2D-ligands in cervical cancer cell lines might be associated with the down-modulation of NKG2D, as well as with changes in the cytotoxic activity of NKL cells after cell-cell contact with the tumor cells.

MHC class I-related chain A and B ligands are differentially expressed in human cervical cancer cell lines

BACKGROUND

Natural killer (NK) cells are an important resource of the innate immune system directly involved in the spontaneous recognition and lysis of virus-infected and tumor cells. An exquisite balance of inhibitory and activating receptors tightly controls the NK cell activity. At present, one of the best-characterized activating receptors is NKG2D, which promotes the NK-mediated lysis of target cells by binding to a family of cell surface ligands encoded by the MHC class I chain-related (MIC) genes, among others. The goal of this study was to describe the expression pattern of MICA and MICB at the molecular and cellular levels in human cervical cancer cell lines infected or not with human papillomavirus, as well as in a non-tumorigenic keratinocyte cell line.

RESULTS

Here we show that MICA and MICB exhibit differential expression patterns among HPV-infected (SiHa and HeLa) and non-infected cell lines (C33-A, a tumor cell line, and HaCaT, an immortalized keratinocyte cell line). Cell surface expression of MICA was higher than cell surface expression of MICB in the HPV-positive cell lines; in contrast, HPV-negative cells expressed lower levels of MICA. Interestingly, the MICA levels observed in C33-A cells were overcome by significantly higher MICB expression. Also, all cell lines released higher amounts of soluble MICB than of soluble MICA into the cell culture supernatant, although this was most pronounced in C33-A cells. Additionally, Real-Time PCR analysis demonstrated that MICA was strongly upregulated after genotoxic stress.

CONCLUSIONS

This study provides evidence that even when MICA and MICB share a high degree of homology at both genomic and protein levels, differential regulation of their expression and cell surface appearance might be occurring in cervical cancer-derived cells.

Procalcitonin and C-reactive protein serum levels as markers of infection in a pediatric population with febrile neutropenia and cancer

BACKGROUND

Procalcitonin and C-reactive-protein are inflammatory markers for sepsis. The authors evaluated their sensitivity and specificity in pediatric patients with cancer and febrile neutropenia.

PROCEDURE

Serum procalcitonin and C-reactive-protein were evaluated. Patients (n = 54) were divided into 2 groups, with severe infection (n = 18) or without documented infection (n = 36).

RESULTS

Procalcitonin and C-reactive protein were significantly higher in the high-risk group. Procalcitonin displayed 72.2% sensitivity and 80.5% specificity. C-reactive-protein had a sensitivity of 77.7% and specificity of 77.2%.

CONCLUSIONS

Procalcitonin is an accurate predictor of bacterial infection in neutropenic children, while C-reactive-protein may be a better screening test in emergency settings.

Positive selection and transplantation of peripheral CD34+ progenitor cells: feasibility and purging efficacy in pediatric patients with neuroblastoma

Peripheral stem cells were mobilized and collected in 20 children with stage 4 neuroblastoma. A total of 37 leukaphereses were performed in the 20 patients. The mean number of collected cells was 5.6 +/- 2.4 x 10(8)/kg (range 1.9-10.5), and the number of collected CD34+ progenitors was 6.1 +/- 6.3 x 10(6)/kg (range 0.75-21.7). CD34-positive selection was performed using the CellPro method. Of the adsorbed cells, 42 +/- 20% (range 4.3-76.6) stained positively for CD34, and the number of positively selected CD34+ cells was 2.0 +/- 1.9 x 10(6)/kg (range 0.09-7.1). The mean recovery of CD34+ cells was 36 +/- 20% (range 6-67). For detection of contaminating neuroblastoma cells before and after CD34-positive selection, a murine antidisialoganglioside GD2 antibody (14.G2a) was used, followed by the alkaline phosphatase antialkaline phosphatase (APAAP) method. Before the positive selection, various numbers of contaminating neuroblastoma cells were found in the leukaphereses of 7 patients. After positive selection, neuroblastoma cells were still detectable in all 7 patients, with a mean log depletion of tumor cells of 1.41 +/- 0.45 (range 0.69-2.13). In 1 patient, contaminating neuroblastoma cells were found only after CD34-positive selection. In 15 of the 20 patients, high-dose chemotherapy was performed, and positively selected CD34+ cells were reinfused in 12 patients. In 10 of these, the mean time to reach > 0.5 x 10(9)/L granulocytes was 12.3 +/- 1.7 days (range 10-16). One patient died at day 7 due to sepsis, and in 1 patient the backup was given at day 15. Because of the low number of collected CD34+ cells, 3 patients were grafted with a combination of unmanipulated PBSC and CD34+ progenitors. In summary, we have shown that positive selection of peripheral CD34+ progenitors is feasible in pediatric patients. However, strategies to improve the recovery of the CD34+ cells and the purging efficacy of this method (i.e., higher enrichment of CD34+ cells, combination of positive and negative selection methods) should be evaluated further.