First experimental proof of Proton Boron Capture Therapy (PBCT) to enhance protontherapy effectiveness.

Protontherapy is hadrontherapy's fastest-growing modality and a pillar in the battle against cancer. Hadrontherapy's superiority lies in its inverted depth-dose profile, hence tumour-confined irradiation. Protons, however, lack distinct radiobiological advantages over photons or electrons. Higher LET (Linear Energy Transfer) 12C-ions can overcome cancer radioresistance: DNA lesion complexity increases with LET, resulting in efficient cell killing, i.e. higher Relative Biological Effectiveness (RBE). However, economic and radiobiological issues hamper 12C-ion clinical amenability. Thus, enhancing proton RBE is desirable. To this end, we exploited the p + 11B → 3α reaction to generate high-LET alpha particles with a clinical proton beam. To maximize the reaction rate, we used sodium borocaptate (BSH) with natural boron content. Boron-Neutron Capture Therapy (BNCT) uses 10B-enriched BSH for neutron irradiation-triggered alpha particles. We recorded significantly increased cellular lethality and chromosome aberration complexity. A strategy combining protontherapy's ballistic precision with the higher RBE promised by BNCT and 12C-ion therapy is thus demonstrated.

Tuberculosis among immigrants from developing countries in the province of Milan, 1993-1996.

SETTING: The Province of Milan, which has high rates of immigration from developing countries, and the Villa Marelli Institute (VMI), Reference Centre for Tuberculosis Control of Lombardy. OBJECTIVE: To describe epidemiology and clinical patterns of tuberculosis among immigrants from developing countries (IDCs) in the Province from 1993 to 1996. DESIGN: Retrospective analysis of the registries of the Regional Bureau for Public Health and of the VMI concerning immigrant patients with active TB living in the Province. Restriction fragment length polymorphism (RFLP) analysis of the available strains to detect recent transmission among immigrants. RESULTS: IDCs represented 22.8% of all TB cases. The standardised incidence rate was eight times higher in IDCs compared to Italians. Of 596 cases notified in IDCs, 524 (87.9%) had been referred at least once to the VMI. Of these, 77.2% were diagnosed within 5 years of arrival, and 86.6% were brought to medical attention because of symptoms. RFLP fingerprinting demonstrated that the mean period of stay in Italy was significantly higher in clustered than in non clustered patients (61.5 versus 37.3 months). Spread to the native population was episodic. CONCLUSIONS: The incidence of TB is higher among more recent immigrants (i.e., Peruvians). TB cases are largely due to reactivation of infection occurring in the country of origin. Preventive measures for early diagnosis of disease or chemoprophylaxis of dormant infection are not regularly performed, but should be implemented for those immigrants at high risk.

Clinical response to chemotherapy and hormone therapy as first treatment after therapeutic ovariectomy in advanced breast cancer patients.

The results of chemotherapy and hormone therapy, administered after relapse of the disease, were evaluated in 106 patients with homogeneous clinical characteristics who were subjected to bilateral ovariectomy for advanced breast cancer, whether the response to castration was favorable or not. In spite of an unfavorable response to the ovariectomy, 40.0% of the patients responded to hormone therapy, whereas 32.5% of the cases did not benefit from the successive hormone therapy, although they had responded to ovariectomy. The contrast, 65%, after favorably responding to ovariectomy, showed regression of the neoplasm after chemotherapy for the relapse. This apparent discordance of the results could be due to the fact that response to castration is not the only valid parameter to identify hormone dependence of a breast cancer and/or that the breast cancer is composed, in various proportions, of hormone-sensitive and chemo-sensitive cells. The predominance of one of these 2 components could determine the response of the neoplasm to therapy. The authors conclude that a more extensive and accurate hormone typing of the patient could give more precise indications for the appropriate therapy.