Radiation in the Elderly: ‘Excellent Alternative’ for Some Tumor Types

TAMPA, Florida-Radiationtherapy is an "excellent alternative" tosurgery and systemic chemotherapyin older cancer patients, according toBabu Zachariah, MD.Although there is only limited informationon the effectiveness and tolerabilityof radiation therapy in theelderly, some studies do show thatradiation is a reasonable therapeuticchoice in this patient population, accordingto Dr. Zachariah, associateprofessor of radiation oncology withthe H. Lee Moffitt Cancer Center,University of South Florida, Tampa."Mortality from radiotherapy israre, and organ function and preservationis very good," said Dr. Zachariah,who reviewed current literatureand described several combinationchemoradiation trials now enrollingolder patients.Clinical Benefit SimilarElderly patients do not appear to beat risk of increased toxicity to normaltissue, such as fibrosis, telangiectasiaor arm edema, several clinical studiessuggest. Likewise, clinical benefit appearssimilar to what is achieved inyounger patients. For example, Dr.Zachariah said, data show that olderwomen with stage I to II breast cancerwho undergo breast-conservation surgeryand radiotherapy have similarrates of overall survival, relapse-freesurvival, and freedom from local failureor distant metastasis vs youngerpatients.Radiation as Alternativeto SurgeryIn lung cancer, the available datasuggest that radiation therapy can bean alternative for patients more than70 years of age who have resectablelung cancer lesions of 4 cm or less,with a 5-year survival rate of close to17% (Cancer 45:698-702, 1980;Radiother Oncol 13:83-89, 1988). Inone study, which included 40 patientsmore than 70 years of age with a Karnofskyperformance status greater than70, the complete response rate was50%, while the 2-year survival rate was56%; the 5-year survival rate of 16%achieved in the study was comparableto that achieved in surgical patients atthe same institution. Toxicity wascomparable to what might be expectedin younger patients (RadiotherOncol 13:83-89, 1988).Radiation might also be used whenradical surgery for prostate cancer isindicated. Dr. Zachariah and colleagueshave reported that, in menmore than 70 years of age with prostatecancer, 85% had a complete clinicalresponse to radiotherapy, while77% achieved biochemical control,with side effects comparable to what isseen in younger patients. A 4-yearsurvival rate of 96% was reported (AnnOncol 9(suppl 3) 84, 1998).CombinedChemoradiotherapyIn bladder cancer, older patientswith good performance status mightbe candidates for concurrent chemoradiotherapy.One study included 54bladder-cancer patients (mean age,66 years) who received fluorouracil(5-FU)/cisplatin chemotherapy withconcomitant bifractionated radiationtherapy. The treatment was well tolerated,and at 3 years, the disease-freesurvival rate was 62% (J Clin Oncol11:2150-2157, 1993). In another study,of MVAC (methotrexate, vinblastine,doxorubicin, and cisplatin) chemotherapy,and radiation in patients morethan 70 years of age, the 3-year survivalrate was 34% (Cancer 80:115-120,1997).Combined chemoradiotherapy isalso well tolerated by elderly patientswho have upper aerodigestive tractcancers. Likewise, it has also provenfeasible in "well selected" older patientswith anorectal carcinoma; Dr.Zachariah said trial results suggest "acceptable"acute toxicity and no severelate toxicity."Very few clinical trials are currentlyopen for older patients," Dr.Zachariah said, describing the one lungcancer study, one breast cancer study,and five active lymphoma trials currentlyrecruiting patients.Lung Cancer StudyThe lung cancer study, sponsoredby CALGB (Cancer and LeukemiaGroup B), is a phase I dose-escalationinvestigation of accelerated 3-D conformalradiation therapy for patientsat least 18 years of age with early non-small-cell lung cancer and poor pulmonaryfunction.Breast Cancer andLymphoma StudiesThe breast cancer study, availablefor patients 60 years or older withstage I or II disease, is a phase IIIrandomized clinical trial of surgerywith or without axillary node dissection,followed by tamoxifen. Radiationtherapy is offered optionally inpatients who underwent conservativesurgery. This trial is sponsored by theInternational Breast Cancer StudyGroup.Two of the five open lymphomatrials are sponsored by MemorialSloan-Kettering Cancer Center. Oneis a phase II study of rituximab (Rituxan)/CHOP (cyclophosphamide [Cytoxan,Neosar]/doxorubicin HCl/vincristine[Oncovin]/prednisone) plusthe radiolabeled monoclonal antibodyyttrium Y90 ibritumomab tiuxetan(Zevalin). Patients must be 60 years ofage or older and have previously untreateddiffuse large B-cell lymphoma.The EORTC (European Organizationfor Research and Treatment ofCancer) Lymphoma CooperativeGroup is sponsoring two more lymphomatrials open to the elderly, includinga phase II study of cyclophosphamide(Cytoxan, Neosar),vincristine (Oncovin), and prednisone,for elderly patients with diffuselarge B-cell lymphoma or peripheralT-cell non-Hodgkin's lymphoma;patients who respond get consolidativeradiotherapy. At the same time,an EORTC phase II to III trial includesolder patients with non-Hodgkin'slymphoma who receive CHOP withor without etoposide, with involvedfieldradiotherapy for some responsivepatients.The fifth lymphoma investigationis a randomized phase III trial of olderpatients who receive cyclophosphamide,doxorubicin, vincristine, andprednisone, with or without rituximab;following chemotherapy, theyreceive radiotherapy to the initial bulkydisease."It is encouraging to see a fewstudies are active for older patientswith cancer," Dr. Zachariah said, "butmore prospective trials combiningchemotherapy and radiation areneeded to improve the currenttherapy."