Compositions for treating cancers of mucosal tissues including breast, prostate, ovary, colon are disclosed which include various combinations of new or conventional anti-estrogen compounds, aromatase inhibitors, immune modulators, immune inhibitors, immune inhibitor mimicking compounds and steroid or thyroid hormones. Methods of predicting susceptibility of a cancer of mucosal origin to treatment with a composition containing an immune inhibitor or an immune inhibitor mimicking compound are also disclosed. Preferred methods include identifying in a specimen of cancer cells the presence of a Poly-Ig (Fc) receptor or Poly-Ig-like (Fc) receptor capable of binding to an immune inhibitor or an immune inhibitor mimicking compound and of mediating immune inhibition of cancer cell growth.