Policy Report: Introducing an Effective National Cancer Control Plan in the Maldives

Background and context: There is no National Cancer Control Plan (NCCP) in the Maldives. The Health Plan has identified cancer as an area with a need for development of separate policy, strategy paper while it is also reflected in the Multi-Stakeholder Action Plan for NCDs. Aim: The main aim of the project is to produce a policy report to guide the development of an effective National Cancer Control Plan (NCCP) in the Maldives. The objectives are to estimate the total period prevalence of cancer in the Maldives (2013-2014); to understand the views of key stakeholders; and synthesize this to develop a policy report and applying the “Cancer Control, Knowledge into Action: WHO Guide for Effective Programmes - in Low and Middle Income Countries”, to the Maldives context to identify priority components in light of the prevalence estimates and views of the key stakeholders. Strategy/Tactics: The policy report will bring together the findings from secondary analysis of quantitative data, analysis of key informant in-depth interviews from stakeholders, using the framework analysis method for qualitative data analysis and applying the “WHO Guide for Effective Programmes - in Low and Middle Income Countries”, to the Maldives context and identify priority components in light of the prevalence estimates and views of the key stakeholders. Outcomes: Among a population of 344,023 people, the estimated total period prevalence for all cancers in the period of 2013-2014 in Maldives is 0.92% (920 cases per 100,000 population). The estimated prevalence is 0.84% for males and 1.01% for females. Oral cancers (including lip, tongue, gum, mouth, and palate) is the most common cancer, followed by eye, breast (with carcinoma in situ), sinuses, skin (melanoma and skin cancers and carcinoma in situ). How common eye cancers and sinus cancers could be reflected as an anomaly in the data as these are uncommon when regional prevalences are compared or is an area where further research is warranted. Thyroid, prostate, lymphomas, leukemias and lung cancers are among the top 10 cancers. The key informant interviews, revealed that there are very limited services available for cancer prevention, diagnosis, treatment and care. What was learned: It is evident that there is a substantial amount of work to be done with regard to cancer control in the Maldives. The high prevalence of cancer and the views of the respondents from the study emphasizes the need for developing a National Cancer Control Plan (NCCP) as an initial step toward comprehensive cancer control efforts in the Maldives. A comprehensive cancer prevention strategy with early detection-early diagnosis and screening should be a priority component for the NCCP, with improvement of diagnosis and treatment services and establishment of a comprehensive palliative and psychosocial care program across the cancer care continuum. This policy report will provide guidance to development of an NCCP with priorities identified.

Competence of oocytes from the B6.YDOM sex-reversed female mouse for maturation, fertilization, and embryonic development in vitro

When the Y chromosome of a Mus musculus domesticus mouse strain is placed onto the C57BL/6J (B6) inbred genetic background, the XY (B6.YDOM) progeny develop ovaries or ovotestes, but not normal testes, during fetal life. At puberty, while some of the hermaphroditic males become fertile, none of the XY sex-reversed females produce litters. We have previously demonstrated that the eggs ovulated from the B6.YDOM ovary undergo fertilization efficiently, but cannot develop beyond the 2-cell stage either in vivo or in vitro. In the present study, we collected oocytes directly from the XY ovary, and examined their maturation, fertilization, and embryonic development in vitro. The results show that the juvenile XY ovary yielded far more fertilizable oocytes by direct collection and in vitro maturation than through in vivo ovulation, but the majority of fertilized eggs failed to reach the blastocyst stage. Hence, developmental incompetence of oocytes in the XY ovary appears to be programmed during oocyte differentiation or growth. Nonetheless, in vitro matured oocytes showed a higher potential of embryonic development than the ovulated eggs, suggesting that fertility of the XY female may be impaired by multiple factors. We hypothesized that poor responsiveness of the XY ovary to gonadotropins, as we have previously demonstrated in testosterone production, may impair follicular development or proper recruitment of oocytes for ovulation. In the present study, we compared 125I-hCG binding in XX and XY ovaries, but did not find a significant difference. Hence, LH activity appears to be impaired after receptor binding in the XY ovary. On the other hand, the pattern of 125I-hCG binding indicated that the majority of antral follicles in the XY ovary failed to undergo normal preovulatory phases, which may explain the lower developmental capacity of eggs after ovulation.

Müllerian inhibiting substance production associated with loss of oocytes and testicular differentiation in the transplanted mouse XX gonadal primordium

The mouse XX gonadal primordium develops seminiferous-like tubules after transplantation into the renal subcapsular site of the adult male or female mouse. We examined the ontogeny of Sertoli cell differentiation in XX gonadal grafts by immunocytochemical staining and organ culture bioassay for Müllerian Inhibiting Substance (MIS). During normal in situ development of the XY gonad, MIS staining was first detected in fetal Sertoli cells at 12 days of gestation (d.g.) and remained intense until 4 days postpartum (d.pp.), after which it gradually diminished with progressive testicular development. In the normal in situ XX gonad, MIS was detected in granulosa cells of growing follicles at 7 d.pp. and thereafter. When the XX gonad at 12 d.g. was grafted beneath the renal capsule, a few testicular cords composed of MIS-positive cells appeared on Day 7 post-transplantation (equivalent to 19 d.g.), much earlier than the normal appearance of MIS production in the intact XX ovary. The ovarian region containing germ cells at the meiotic prophase was unstained for MIS in the same sections. The incidence of XX gonadal grafts containing MIS-positive testicular cords and the number of such cords per gonadal graft steadily increased from Day 7 to Day 14 post-transplantation. Germ cells were absent or scarce inside the MIS-positive testicular cords. The MIS bioactivity in both control gonads and gonadal grafts coincided with the immunocytochemical staining for MIS. These results support the hypothesis that XX cells differentiate into Sertoli cells as a consequence of oocyte loss in the gonadal graft.

Delay of testicular differentiation in the B6.YDOM ovotestis demonstrated by immunocytochemical staining for müllerian inhibiting substance

It has been found that when the Y chromosome from Mus musculus domesticus (YDOM) is placed onto the C57BL/6J (B6) mouse background, the XY progeny (B6.YDOM) develop ovaries or ovotestes but not normal testes during fetal life. We examined the ontogeny of the abnormal testicular differentiation in the B6.YDOM ovotestis by immunocytochemical staining for Müllerian inhibiting substance (MIS). We found that the B6.YDOM ovotestis initiated testicular differentiation later in development than did the control B6 testis. When the YDOM was transferred onto the SJL J mouse background by crossing B6.YDOM males with SJL/J females, all XY progeny developed normal testes. The onset of testicular differentiation was at the same developmental stage as in the B6 male fetus. These results suggest that the delay of testicular differentiation is not due to the effect of the YDOM chromosome itself, but due to improper interaction of the testis-determining gene on the YDOM chromosome with autosomal genes of B6. In addition, we found a close correlation between the arrest of germ cells at the prespermatogonia stage and MIS production of adjacent somatic cells in the B6.YDOM ovotestis. This result may support the hypothesis that MIS is involved in the regulation of germ cell differentiation.

Regulation of testicular differentiation and testosterone production in the fetal mouse gonad in vitro

The objective of the present study was to develop a chemically-defined medium in which early stages of testicular differentiation can be investigated in an organ culture system. Mouse gonadal primordia were explanted before and after initiation of morphological sex differentiation, i.e. 11 and 12 day of gestation (d.g.), respectively. We found that a combination of human albumin fraction, insulin (or IGF-I), and sodium pyruvate promoted testicular organization of gonadal explants of 11 d.g., but not those of 12 d.g. Insulin also increased the production of testosterone from testicular explants of 11 d.g., but not those of 12 d.g. For the younger explants, progesterone was more efficient than pregnenolone as a steroid precursor during the first day of culture, but the maximum effect of pregnenolone was much higher than that of progesterone in later stages. The responsiveness to human chorionic gonadotropin increased gradually along with testicular organization. The addition of either serum or pregnenolone prominently increased the activity of delta 5-3 beta hydroxysteroid dehydrogenase in testicular explants of 11 d.g., but not the number of positive cells as demonstrated by histochemical staining. These results suggest that insulin (or IGF-I) is required during the initial phase of testicular organization, which is reflected by an increase in testosterone production and sensitivity to gonadotropins.