Guidelines for Complications of Cancer Treatment Vol VIII Part B

modality treatment than RT alone (6.1 vs. 4%, p=0.015).Relative risk was higher with bigger RT field sizecorresponding to 2.1, 4.2 and 5.1 for mantle, subtotal nodalirradiation (STNI) and total nodal irradiation (TNI)respectively (8). A recent study by Constine et al., (9) has foundpositive correlation of risk of SMN with radiation dose. Thestandardized incidence ratio (SIR) were 11.7, 12.5, and 16.5with doses 35 Gy respectively(p=0.0085). Apart from the carcinogenicity of radiation therapyand chemotherapy, risk of second primary is also influencedby other known aetiologies of the solid tumor. Young age atmantle irradiation is associated with significantly higher riskof breast cancer. Smoking has been reported to multiply theoccurrence of carcinoma lung in HD survivors. With the useof non alkylating chemotherapy drugs, abbreviated RT fieldsand doses, the incidence of SMN in long-term survivors ofHD is likely to decrease.Head and Neck Cancer: The mucosa of the upper aerodigestivetract is at risk of ‘field carcinogenesis’ and isassociated with increased risk of second malignancies. Thisincreased risk is largely attributed to consumption of tobaccoand alcohol. Recent SEER data of 27,985 patients withlocalized squamous cell HNC (excluding thyroid and salivarygland tumor) treated from 1973 -1997 was analysed to estimatethe risk of second head and neck cancers with or without RT.Details of RT doses and use of tobacco and alcohol was notavailable. It showed 15 year incidence of second head andneck carcinomas to be 7.7% with and 10.5% without RT (HR0.71, p=0.0001). This data suggests potential benefit of RT ineliminating occult foci of second cancer (10).Testicular Cancer: Both leukemias and various solid tumorincluding gastrointestinal, bladder, prostate lung andcontralateral testes cancers have been reported in long-termsurvivors of testicular cancers. These have been largely286