HEIGHTS OF SPECULATIONS

It is generally said that infiltration of Lymphocytes in the tumor points to an immune response against the tumor and therefore imparts a good prognosis, and we did mention this earlier.  But now comes the mitigation to this message, when those lymphocytes are TREG cells the picture is not so clear any more...
"In cancer such as Breast Cancer, there are data that intratumoral Treg cells confer poorer prognosis, in colorectal cancer, Treg cells convey a better prognosis."(Clurman)  Just take a note of this!

Remember Treg are T cell regulators that "maintain tolerance by suppressing expansion of effector cells directed against self Antigen".  If tumors comes from you, than they can have "self Antigen" and will get away with it! and attack you, protected by these Treg cells!  Looking under these perspectives, it now becomes critical to know what Lymphocyte is in the tumor.  A Treg T cell or a true Activated T cell.   let's work at discerning these things before we comment on prognosis!

This point is very emphasized in clinical practice by the example of Ipilimumab.  It is said that its effect resides in the removal of (check point) inhibitory effects of a T cell Regulator (such as the Treg discussed here) CTLA4.  Removing these inhibitory influences unleashes the full might of the Activated T cell against the cancer.  But the side effect to this is that tolerance of normal tissue is low leading to immune attack of even normal tissue.  Cases of Colitis,dermatitis hepatitis, thyroid dysfunction and Stevens Johnson syndrome have been reported, so help you God, Colonic perforation even have been reported.   But yes it is one of the only drug which in recent years or decades, has improved survival in Melanoma, and that is a big first.