The Inside Edge (Dec 2009)
Infertility is a significant side-effect in young patients who are undergoing chemotherapy. Researchers in Italy have described a mechanism that accounts for the negative effects of chemotherapy on female fertility, as well as a potential way of preventing this.Their study, involving female mouse germ cells, showed that cisplatin treatment induced germ cell death by activating an enzyme known as c-Abl. When this enzyme mutates, it causes chronic myeloid leukaemia, which can be therapeutically targeted with imatinib. The researchers found that treating the mouse germ cells with imatinib counteracted cisplatin-induced cell death. They conclude that imatinib may have a role in preserving germ cells and thus fertility during chemotherapy. (Gonfloni S, Di Tella L, Caldarola S et al. Nat Med 2009;15(10):1179-85)
Preclinical studies have shown that local photodynamic therapy (PDT) can enhance systemic immunity to tumours, but this has not been investigated after clinical PDT. US researchers have examined the impact of PDT for basal cell carcinoma (BCC) on systemic immune response to Hip1, a tumour antigen associated with BCC. Lesions were either treated with PDT or surgically removed; blood was collected immediately before or seven to 10 days after treatment to assess the response to Hip1. Immune recognition of Hip1 increased significantly in patients treated with PDT compared with surgery. Immune reactivity after PDT was inversely correlated with treatment area and light dose. (Kabingu E, Oseroff AR, Wilding GE et al. Clin Cancer Res 2009;15(13):4460-6)
Antioxidants are generally perceived as beneficial, but a US study has shown that they can sometimes promote the survival and proliferation of cancer cells. Normal epithelial cells die if they detach from the extracellular matrix. However, in breast cancer, cancer-causing genes such as ERBB2 can provide survival signals to detached tumorigenic cells. This study showed that cell detachment also causes metabolic defects, but that these can be 'rescued' by ERBB2 and by antioxidants, which appear to boost cellular energy levels via fatty acid oxidation. The research was undertaken using mammary epithelial cells and there is no evidence as yet of any implications for patients. (Schafer ZT, Grassian AR, Song L et al. Nature 2009;461:109-13)
Aromatase inhibitors suppress estrogen and may increase the risk of carpal tunnel syndrome in postmenopausal women receiving adjuvant therapy for early breast cancer. UK researchers analysed 100-month median follow-up data from postmenopausal women in the two monotherapy arms of the ATAC trial (anastrozole, n = 3,092; tamoxifen, n = 3,094) and found 80 cases (2.6 per cent) of carpal tunnel syndrome reported in the anastrozole arm, compared with 23 (0.7 per cent) for tamoxifen. The risk of carpal tunnel syndrome was greater in women who had used HRT or received chemotherapy, while those aged 60 years or older at entry had a lower risk. Despite the association of carpal tunnel syndrome with anastrozole use, the authors say it has little impact on the overall risk-benefit ratio for the drug. (Sestak I, Sapunar F, Cuzick J. J Clin Oncol 2009;27(30):4961-5)
Studying pet dogs with cancer could aid the diagnosis and treatment of human cancers, say scientists at the National Cancer Institute in Bethesda, US. They describe a continuing initiative in which spontaneously occurring cancers in dogs are being studied to inform the development of new cancer drugs, devices and imaging strategies for human cancer patients. Naturally occurring tumours in dogs have clinical and biological similarities to human cancers and treatment is comparable to that in humans, involving surgery, radiotherapy and chemotherapy. Furthermore, owners are often motivated to pursue novel and investigational treatments for their pets. (Gordon I, Paoloni M, Mazcko C et al. PLoS Med 2009;6(10):e1000161)
Originally published in the December 2009 edition of MIMS Oncology & Palliative Care.