BREAST-CANCER IMMUNOTHERAPY - CURRENT STATUS AND FUTURE-PROSPECTS

The development of an immunotherapeutic approach to cancer is the conc ern for many immunologists, but despite the impressive progress over t he past decade, such as the identification of tumour antigens and anti genic peptides as potential targets, there are still many obstacles in eliciting an effective immune response to eradicate cancer. Mucins ha ve attracted interest as potential targets for immunotherapy in the de velopment of vaccines for cancers expressing Mucin 1 (MUC1; e.g. breas t, pancreas, ovary etc.). All of the identified targets for cancer, in cluding MUC1, are normal proteins; however MUC1 expressed on tumours c an be considered as tumour specific due to their overexpression, alter ed glycosylation and its ubiquitous distribution on the cell surface r ather than at the secretory pole in adenocarcinomas. These observation s have led to the development of several different approaches to immun ize against breast cancer using synthetic carbohydrates or peptides co njugated to carriers and given together with a variety of adjuvants to elicit the appropriate immune response. Mannan, a polymannose carbohy drate isolated from the cell wall of yeast, is an appropriate and effe ctive protein carrier for eliciting a cellular (T-1-type) or humoral ( T-2-type) immune response depending on the mode of conjugation (oxidiz ed or reduced). In addition, mannan holds promise and opens many avenu es as a carrier for vaccine development for other antigens. Several cl inical trials are in progress to evaluate the immunogenicity of MUC1 a nd its suitability as to use for immunotherapy/vaccine for breast canc er.