I had not heard anything about this, so I'm doing some research on it. Interesting findings so far:
Aloe inhibits growth of Merkel cell carcinoma (a type of skin cancer) cells in vitro
Aloe results in keratinocyte proliferation in a dose-dependent manner
The following quote is from HERE.
Some studies have indicated that aloe vera may have anticancer effects. Emodin, an extract of aloe vera, can inhibit cell proliferation and induce apoptosis in human liver cancer cell lines through p53- and p21-dependent pathway (11). Acemannan, a carbohydrate fraction derived from aloe vera leaf, can stimulate cytokine production in mouse macrophage cell line (17). This component also has immunomodulating activities by inducing maturation of dendritic cells (13). Another in vitro study has indicated aloeride, a polysaccharide obtained from aloe vera juice, as a potent immunostimulator by increasing NF-kappa B activities (14). A compound, di(2-ethylhexyl)phthalate (DEHP), isolated from aloe vera can inhibit leukemic cells in vitro (16)