The Effect of MHC Antigen Matching Between Donors and Recipients on Skin Tolerance of Vascularized Composite Allografts.

The emergence of skin-containing vascularized composite allografts (VCAs) has provided impetus to understand factors affecting rejection and tolerance of skin. VCA tolerance can be established in miniature swine across haploidentical MHC barriers using mixed chimerism. Because the deceased donor pool for VCAs does not permit MHC antigen matching, clinical VCAs are transplanted across varying MHC disparities. We investigated whether sharing of MHC class I or II antigens between donors and recipients influences VCA skin tolerance. Miniature swine were conditioned nonmyeloablatively and received hematopoietic stem cell transplants and VCAs across MHC class I (n = 3) or class II (n = 3) barriers. In vitro immune responsiveness was assessed, and VCA skin-resident leukocytes were characterized by flow cytometry. Stable mixed chimerism was established in all animals. MHC class II-mismatched chimeras were tolerant of VCAs. MHC class I-mismatched animals, however, rejected VCA skin, characterized by infiltration of recipient-type CD8+ lymphocytes. Systemic donor-specific nonresponsiveness was maintained, including after VCA rejection. This study shows that MHC antigen matching influences VCA skin rejection and suggests that local regulation of immune tolerance is critical in long-term acceptance of all VCA components. These results help elucidate novel mechanisms underlying skin tolerance and identify clinically relevant VCA tolerance strategies.

Kidney-induced cardiac allograft tolerance in miniature swine is dependent on MHC-matching of donor cardiac and renal parenchyma.

Kidney allografts possess the ability to enable a short course of immunosuppression to induce tolerance of themselves and of cardiac allografts across a full-MHC barrier in miniature swine. However, the renal element(s) responsible for kidney-induced cardiac allograft tolerance (KICAT) are unknown. Here we investigated whether MHC disparities between parenchyma versus hematopoietic-derived "passenger" cells of the heart and kidney allografts affected KICAT. Heart and kidney allografts were co-transplanted into MHC-mismatched recipients treated with high-dose tacrolimus for 12 days. Group 1 animals (n = 3) received kidney and heart allografts fully MHC-mismatched to each other and to the recipient. Group 2 animals (n = 3) received kidney and heart allografts MHC-matched to each other but MHC-mismatched to the recipient. Group 3 animals (n = 3) received chimeric kidney allografts whose parenchyma was MHC-mismatched to the donor heart. Group 4 animals (n = 3) received chimeric kidney allografts whose passenger leukocytes were MHC-mismatched to the donor heart. Five of six heart allografts in Groups 1 and 3 rejected <40 days. In contrast, heart allografts in Groups 2 and 4 survived >150 days without rejection (p < 0.05). These data demonstrate that KICAT requires MHC-matching between kidney allograft parenchyma and heart allografts, suggesting that cells intrinsic to the kidney enable cardiac allograft tolerance.

Vascularized composite allograft tolerance across MHC barriers in a large animal model.

Vascularized composite allograft (VCA) transplantation can restore form and function following severe craniofacial injuries, extremity amputations or massive tissue loss. The induction of transplant tolerance would eliminate the need for long-term immunosuppression, realigning the risk-benefit ratio for these life-enhancing procedures. Skin, a critical component of VCA, has consistently presented the most stringent challenge to transplant tolerance. Here, we demonstrate, in a clinically relevant miniature swine model, induction of immunologic tolerance of VCAs across MHC barriers by induction of stable hematopoietic mixed chimerism. Recipient conditioning consisted of T cell depletion with CD3-immunotoxin, and 100 cGy total body irradiation prior to hematopoietic cell transplantation (HCT) and a 45-day course of cyclosporine A. VCA transplantation was performed either simultaneously to induction of mixed chimerism or into established mixed chimeras 85-150 days later. Following withdrawal of immunosuppression both VCAs transplanted into stable chimeras (n=4), and those transplanted at the time of HCT (n=2) accepted all components, including skin, without evidence of rejection to the experimental end point 115-504 days posttransplant. These data demonstrate that tolerance across MHC mismatches can be induced in a clinically relevant VCA model, providing proof of concept for long-term immunosuppression-free survival.

Skin grafts from genetically modified α-1,3-galactosyltransferase knockout miniature swine: A functional equivalent to allografts.

Burn is associated with a considerable burden of morbidity worldwide. Early excision of burned tissue and skin grafting of the resultant wound has been established as a mainstay of modern burn therapy. However, in large burns, donor sites for autologous skin may be limited. Numerous alternatives, from cadaver skin to synthetic substitutes have been described, each with varying benefits and limitations. We previously proposed the use of genetically modified (alpha-1,3-galactosyl transferase knockout, GalT-KO) porcine skin as a viable skin alternative. In contrast to wild type porcine skin, which has been used as a biologic dressing following glutaraldehyde fixation, GalT-KO porcine skin is a viable graft, which is not susceptible to loss by hyperacute rejection, and undergoes graft take and healing, prior to eventual rejection, comparable to cadaver allogeneic skin. In the current study we aimed to perform a detailed functional analysis of GalT-KO skin grafts in comparison to allogeneic grafts for temporary closure of full thickness wounds using our baboon dorsum wound model. Grafts were assessed by measurement of fluid loss, wound infection rate, and take, and healed appearance, of secondary autologous grafts following xenograft rejection. Comparison was also made between fresh and cryopreserved grafts. No statistically significant difference was identified between GalT-KO and allogeneic skin grafts in any of the assessed parameters, and graft take and function was not adversely effected by the freeze-thaw process. These data demonstrate that GalT-KO porcine grafts are functionally comparable to allogeneic skin grafts for temporary closure of full thickness wounds, and support their consideration as an alternative to cadaver allogeneic skin in the emergency management of large burns.

Local therapy, systemic benefit: challenging the paradigm of biological predeterminism.

This paper briefly reviews the historical evolution of paradigms that have been purported to characterise the clinical behaviour of breast cancer, with the intention of guiding treatment approaches. Results from randomised clinical trials and the explosion of knowledge in the area of cancer biology have discredited the monolithic paradigms that had dominated thinking about breast cancer in the past. Contemporary notions of breast cancer biology recognise that, although some cancers disseminate well before becoming clinically detectable, acquisition of a metastatic phenotype can occur at any point (or not at all) in the local evolution of the tumour. As a consequence, both systemic and timely local--regional therapies can be expected to influence disease dissemination and patient survival. This is consistent with results observed in clinical trials, overviews of which indicate that prevention of four local recurrences will, on the average, prevent one death from breast cancer. Optimisation of local-regional treatment is an important goal in breast cancer management.

Prospective pilot study of sildenafil for treatment of postradiotherapy erectile dysfunction in patients with prostate cancer.

PURPOSE: Erectile dysfunction is a common late complication patients may experience after external-beam radiotherapy for prostate cancer. The efficacy and safety of oral sildenafil to correct sexual dysfunction caused by external-beam radiotherapy was studied in patients participating in our prospective trial. PATIENTS AND METHODS: Thirty-five assessable patients participated in this prospective pilot study. Using a 25-point scale based on the International Index of Sexual Function, erectile dysfunction was assessed weekly, during which time patients received sildenafil 100 mg orally once a week for 6 consecutive weeks. Response was defined as a score of 18 or more, corresponding to at least one successful attempt at sexual intercourse per week. RESULTS: Thirty patients (86%) completed the 6-week study. Seventy-seven percent of these patients had significantly improved erectile function, allowing recovery of full capacity for sexual intercourse. Of 27 patients not receiving concomitant hormone treatment, failure to respond was observed in only four patients (15%) compared with four (50%) of eight patients receiving hormonal treatment during the study. The time course of response was gradual, with 40%, 57%, 66%, 69%, and 74% responding at weeks 1 through 5, respectively. Therapy was generally well tolerated. The most frequently reported side effects in patients were flushing (37%), transient headache (17%), and dyspepsia (9%). No patient reported priapism, and no cardiovascular event or death was observed. After response, 12 patients (34%) reported the ability to achieve and maintain an erection sufficient for intercourse in the absence of sildenafil (ie, 24 hours to 6 days after taking the medication). CONCLUSION: This study suggests that oral sildenafil is well tolerated and can reverse erectile dysfunction after radiotherapy in a substantial proportion of prostate cancer patients.

Renal toxicity after allogeneic bone marrow transplantation: the combined effects of total-body irradiation and graft-versus-host disease.

PURPOSE: To evaluate retrospectively the cumulative risk probability and factors correlated with renal dysfunction after allogeneic bone marrow transplantation (BMT). PATIENTS AND METHODS: From October 1984 to July 1994, 84 patients with malignant hematopoietic diseases received allogeneic BMT after conditioning with high-dose chemotherapy and total-body irradiation (TBI). Seventy-nine patients with normal renal function before conditioning are included in this study. Conditioning included high-dose cyclophosphamide without (n = 46) or with (n = 33) other agents (daunorubicin, busulfan, cytarabine, and thiotepa) followed by TBI. The TBI dose prescribed to the center of the abdomen was 10 Gy for 24 patients, 12 Gy for 32, and 13.5 Gy for 23. In vitro T-cell depletion was undertaken in 48 cases. The post-BMT nephrotoxicity of aminoglycosides, vancomycin, amphotericin, and cyclosporine was assessed. Time to renal dysfunction was defined as the time to a persistent increase of serum creatinine (SCr) level greater than 110 mumol/L. The potential influence of sex, age, diagnosis, chimerism, and graft-versus-host disease (GvHD) on renal dysfunction was also assessed. RESULTS: The 18-month probability of renal dysfunction-free survival (RDFS) for the whole group was 77%. Only TBI dose and presence of GvHD were significantly correlated with renal dysfunction by multivariate analysis. The 18-month probabilities of RDFS were 95%, 74%, and 55% for the patients conditioned with 10, 12, and 13.5 Gy, respectively. The 18-month RDFS probabilities were 88% and 61% for patients without and with GvHD, respectively. Combining both variables, we have defined two risk categories: low-risk (ie, 10 Gy TBI with/without GvHD and 12 Gy TBI without GvHD) and high-risk (ie, 12 Gy TBI with GvHD and 13.5 Gy TBI with/without GvHD). The predicted 18-month RDFS rates were 93% and 52% for the low- and high-risk groups, respectively. CONCLUSION: Renal dysfunction after allogeneic BMT is strongly related to the delivered TBI dose (and dose per fraction) and to the presence of GvHD. Renal shielding should be recommended if a TBI dose greater than 12 Gy (fractionated twice daily over 3 days) is to be prescribed. Furthermore, in those cases with a high risk of developing GvHD (eg, unrelated allogeneic BMT, absence of T-cell depletion), these data suggest that kidney doses greater than 10 Gy should be avoided.

Why are local recurrences after breast-conserving therapy more frequent in younger patients?

The influence of patient age on risk of recurrence in the breast was retrospectively studied in 496 stage I-II invasive ductal carcinomas treated by macroscopically complete primary tumor excision followed by radiotherapy. With a median follow-up of 71 months, local recurrence occurred in 13 of 62 (21%) patients younger than 40 years, compared with 48 of 434 (11%) older patients (P less than .025). Cox multivariate analysis of 18 parameters identified four that significantly determined risk: major lymphocytic stromal reaction (MCR), unsatisfactory resection margins, increasing histologic grade, and extensive intraductal cancer (DCIS) within the primary tumor. Compared with older patients, those younger than 40 years had tumors that more often exhibited MCR (36% v 20%, P less than .01), histologic grade 3 (42% v 28%, P less than .025), and very extensive DCIS (21% v 6%, P less than .001). The status of resection margins did not differ significantly between younger and older patients. Restriction of Cox analysis to patients younger than 40 indicated that risk was adequately described by MCR and percentage of DCIS, without consideration of grade or margins. For patients younger than 40, local failure occurred in four of five (80%) tumors with both MCR and more than 50% DCIS, in eight of 25 (32%) with either, and one of 32 (3.1%) with neither of these morphologic features. This study suggests that the higher local failure risk observed in patients younger than 40 years reflects the greater prevalence of certain morphologic characteristics in breast cancers in younger patients. Age itself does not appear to be an independent determinate of risk.

Factors influencing the risk of local recurrence in the breast.

This paper reviews what is currently known regarding possible factors influencing the risk of local failure in the breast after conservative surgery and radiation therapy for clinical stage I and II breast cancer. The best established features correlating with increased risk are young age at time of primary therapy, and the presence of an extensive intraductal component within the primary tumour. The interactions of tumour- and treatment-related factors is complex, but adequacy of surgical excision, quality of radiation therapy technique, and use of systemic therapy all appear to contribute to risk reduction.

Breast conservation in the 21st century.

As breast cancers are diagnosed at increasingly early stages, and there is little biological rationale for mastectomy in most patients, breast conservation is likely to be practised with increased frequency in the future. Newer breast imaging techniques, particularly magnetic resonance imaging (MRI), should contribute to improved pretherapy planning, both aiding in the selection of patients for conservation approaches, and estimating the residual tumour burden following minimally invasive surgical interventions. Image-guided tumour mapping may permit local treatment to be individualised, most importantly allowing definition of subgroups not requiring treatment directed at the whole breast. Moreover, interventional radiology opens new possibilities for focalised treatments, which may come to be employed in the management of small lesions. The increasing use of primary chemo- or chemoendocrine therapy will also tend to favour the option of breast conservation. Functional imaging techniques, including MRI, may prove valuable in the assessment of response to medical therapy, allowing more individualised use of radiotherapy and surgery. Technical progress and the development of biological response modifiers may further improve the therapeutic ratio associated with radiation treatment.

Is breast conservation after local recurrence feasible?

The feasibility of conservative salvage surgery was addressed in a clinicopathologic study of the results of wide excision for 50 selected parenchymal intramammary recurrences after standard breast conserving treatment. After median follow-up of 51 months, 16 (32%) second local failures were observed (5-year local control 62%). Cox multivariate analysis of 18 parameters indicated that only disease-free interval and resection margins significantly influenced local control. 5-year local control was 92% for recurrences occurring after 5 years vs. 49% for shorter intervals, and 73% for negative vs. 36% for positive or indeterminate margins. Local control appeared independent of morphologic features, initial tumour stage, patient age, recurrent tumour size and location. Median survival after second local failure was 33 months; tertiary therapy obtained ultimate local-regional control in 8 of 16 cases. The authors conclude that wide excision is a particularly satisfactory alternative to salvage mastectomy for late recurrences. Negative margins are essential. Further study will be required to establish additional guidelines allowing improved patient selection.

Late breast recurrence after lumpectomy and irradiation.

For 276 patients with early breast cancer followed from 10-21 years after lumpectomy and radiotherapy, the recurrence rate in the treated breast was 15.6%, and 7.2% developed contralateral breast cancer. Only 63% of breast recurrences occurred within 5 years, and the remainder were "late failures," with 5 of the 43 recurrences observed after 10 years. The proportion of failures occurring late was greater for T1 than for T2 tumors (53% vs 25%). Twenty-six percent of early recurrences were inoperable, and an adverse impact of early recurrence on 10-year survival was clearly demonstrable. Late recurrences were all operable and did not appear to be associated with decreased survival. Only 16 of the 36 patients (44%) with operable breast recurrence ever developed metastatic disease, and 5 year survival following salvage therapy was 62%. Although the treated breast remains at continuous cancer risk even beyond 5 year, the prognosis of late recurrence appears quite similar to that of contralateral breast cancer. We do not consider the phenomenon of late recurrence to lend support to a policy of primary mastectomy, just as the existence of contralateral breast cancer does not justify routine "prophylactic" contralateral mastectomy.

The impact of gap duration on local control in anal canal carcinoma treated by split-course radiotherapy and concomitant chemotherapy.

PURPOSE: To investigate the potential benefit of reducing the intersequence gap in patients with anal cancer treated with split-course chemoradiotherapy. METHODS: The study group consisted of 90 patients with anal squamous carcinoma treated between 1981 and 1998, using concomitant chemotherapy (CT) and radiation (RT). Median age was 65 years (range 41-87). RT was delivered in a split course, with a median gap of 37.5 days (range 4-97) between sequences. First (pelvic) sequence delivered a median dose of 40 Gy (range 36-50.4), using AP/PA megavoltage photon beams. Boost treatment (median dose 20 Gy, range 13-26) consisted of either Iridium-192 implantation (49 patients) or external beam RT (41 patients). CT consisted of 1-2 cycles of a 5-day continuous infusion of 5-fluorouracil and bolus mitomycin C, usually administered during the first week of each RT course. Median follow-up was 76.2 months. Univariate and multivariate analyses were performed to determine the factors associated with locoregional control (LRC). RESULTS: Five-year actuarial LRC was 72.5%. Factors associated with poorer LRC (univariate) were: age < or = 65, male gender, and gap > 37.5 days. Number of CT cycles (1 vs. 2 or more), boost technique (brachytherapy vs. external), and T-stage were not significantly associated with LRC. In multivariate analysis, only age (p = 0.01), and gap (p = 0.02) retained their significance. In patients older than 65 years, LRC was 92.3% and 75% for shorter and longer gaps, respectively. In younger patients, the corresponding values for LRC were 73.7% and 50%. CONCLUSION: In anal cancers, split-course RT with > 50 Gy dose delivery is difficult to avoid because of acute toxicity. The present analysis suggests that shortening the gap contributes to optimizing LRC. Gaps longer than 5 weeks correlated with poorer LRC, with especially unsatisfactory results observed in younger patients.

Influence of modifications in breast irradiation technique on dose outside the treatment volume.

PURPOSE: There is increasing interest in potential long-term effects of radiotherapy (RT) in patients treated for breast cancer, particularly those in whom long-term survival can be expected. The purpose of the present study was to determine the effects of treatment techniques, including patient positioning (supine vs. prone) on the absorbed dose in organs at a distance from the treatment volume in breast RT. METHODS AND MATERIALS: Dose distribution was studied in a Rando-Alderson phantom, modified with a simulated left breast of tissue-equivalent material. RT delivery was studied using 60Co and 6 MV x-ray beams, as well as electrons and a 192Ir source for tumor bed boost RT. Doses were measured in several organs and tissues of interest using LiF thermoluminescent dosimeters. Tangential breast RT was simulated using both supine and prone positioning. RESULTS: Peripheral doses generally decreased approximately exponentially with distance from the edge of the treatment field. Peripheral doses in various target organs were significantly higher for supine than for prone tangential breast RT (for 50 Gy prescribed dose): 0.50 Gy vs. 0.25 Gy for the upper abdomen, 0.05 Gy vs. 0.02 Gy for pelvic organs, 0.17 Gy vs. 0.08 Gy for active bone marrow, and 0.47 Gy vs. 0.12 Gy for ipsilateral lung (discounting lung in primary beam). CONCLUSIONS: The present study suggests that peripheral doses in several organs and tissues of interest can be reduced by 40 to 75% by prone tangential breast RT. These results may have implications for future strategies in the treatment of screen-detected breast cancer.

Conservation treatment of early breast cancer: long term results and complications.

Results of radiation therapy following breast-conserving surgery were analyzed for 410 patients with clinical Stage I-II mammary carcinoma having a minimum and median follow-up time of 5 years and 11 years, respectively. Crude survival rates were 82.2% at 5 years, 62.5% at 10 years, and 45.4% at 15 years. Local-regional recurrence was observed in 9.7% of patients. Seventy-five percent of these recurrences could be controlled locally by further treatment. Both local recurrences and metastatic deaths were more frequent in patients in clinical Stage II and in patients 40 years of age or younger. The cosmetic result was judged good to excellent in 77% of patients, with unacceptable results in 6.7%. The majority of poor results were seen in patients receiving 60 Gy or more to the entire breast. Arm edema occurred in 25% of patients having had axillary dissection, and in 3.4% of patients without axillary surgery. Edema was confined mainly to patients having had axillary doses of 60 Gy or more, and was never disabling. This study demonstrates that excellent long-term results are obtainable with breast-conserving techniques in early breast cancer. Satisfactory cosmetic results and a very low complication rate can be expected if extensive axillary surgery is avoided in conjunction with axillary radiation, and if the radiation dose applied to large treatment volumes is restricted to 50 Gy.

Contralateral breast cancer and other second malignancies in patients treated by breast-conserving therapy with radiation.

Metachronous contralateral breast cancers and other second malignancies were evaluated in 2,850 patients treated between 1960 and 1981 primarily with radiotherapy (RT) either alone or following breast-conserving surgery. One hundred eighty-four contralateral cancers were observed in 22,491 patient-years of observation (818 per 10(5) patient-years), with a cumulative probability of 4.5% at 5, 7.9% at 10, and 11% at 15 and 20 years. Compared to patients with unilateral tumors, those destined to develop contralateral cancers were younger (mean age 51.9 vs 56.6) and more often gave a family history of breast cancer. Contralateral breast cancers were more frequent for more extensive tumors (T3 10% vs T1-26%; with inflammatory signs 10.6% without 6%), and in patients with ipsilateral local recurrence (with 9.1%, without 5.6%). Patients with contralateral cancers had a significantly less favorable survival experience (15-year actuarial survival after primary therapy 42%) than patients without contralateral cancer (15-year survival 65.5%). In early stage patients treated with conservative surgery and RT, contralateral cancer was not prognostically more favorable than ipsilateral breast recurrence. Among 72 other second malignancies (320 per 10(5) patient-years) were 2 soft tissue sarcomas in the irradiated area. This corresponds to an incidence of 21 cases per 10(5) patient-years for survivors beyond the fifth year. The possible influence of RT on contralateral cancers and other second malignancies is discussed.

Dose variation at bone/titanium interfaces using titanium hollow screw osseointegrating reconstruction plates.

PURPOSE: To evaluate dose variations at bone/titanium interfaces in an experimental model designed to simulate postoperative radiotherapy in patients with mandibular reconstructions using a titanium hollow-screw osseointegrating reconstruction plate (THORP) system. MATERIALS AND METHODS: The model consisted of a 25 x 25 x 10 mm3 block of fresh bovine femoral diaphysis, to the surface of which a segment of THORP system reconstruction plate was fixed by means of a solid titanium screw 4 mm in diameter and 10 mm in length. Using specially designed thermoluminescent dosimeters (TLD) 2 mm in diameter and 0.13 mm in thickness, dose measurements were carried out at four distances from the screw axis (0.1, 0.3, 0.6, and 1 mm). 60Co and 6-MV photon beams were used at incidences both perpendicular and parallel ("axial") to the screw axis. RESULTS: For 6-MV X-ray beams incident perpendicular to the screw axis, the maximum dose enhancement (due to backscatter) and the maximum dose reduction (due to attenuation) at the bone/titanium interface were 5% (+/- 2%) and 6% (+/- 2%), respectively. The corresponding values for 60Co beams were 6% (+/- 5%) and 10% (+/- 5%). For the axial incidences, a maximum dose enhancement of 5-7% was noted for both 6-MV X-rays and 60Co for beams incident on the surface containing the THORP plate segment, whereas beams incident on the opposite surface induced only a very small dose enhancement (2-3%). CONCLUSION: Using a new experimental model, TLD measurements showed only marginally significant dose variations at bone/titanium interfaces around THORP screws, all measured values being very close to the uncertainty limits (+/- 5%) associated with the method. For both 60Co and 6-MV beams, dose variations appeared smaller for axial than for perpendicular incidences. Because photon beams used in head and neck cancer treatment are most often directed parallel to the screw axes, these results suggest that failures of prosthetic osseointegration are unlikely to be explained by an overdosage at the bone/titanium interface.

The second ten years: long-term risks of breast conservation in early breast cancer.

A retrospective cooperative study was undertaken to analyze the fate of 300 clinical Stage I and II breast cancer patients who were alive and apparently cured with both breasts preserved, 10 years following primary limited surgery with irradiation. All patients had been treated by tumor excision, with or without axillary dissection, followed by megavoltage radiation therapy. Follow-up ranged from 10.5 to 26 years, median 14.5 years. The overall actuarial survival (Kaplan-Meier) of the 300 "cured" patients was 86% at 15 years and 78% at 20 years, with 38.5% of deaths attributable to breast cancer. The actuarial probability of remaining free of metastatic disease was 91% at both 15 and 20 years, independent of age or clinical stage. Sixteen patients (5.3%) developed recurrent cancer in the treated breast beyond the tenth year, the actuarial probability of remaining free of breast recurrence being 94% and 90% at 15 and 20 years, respectively. Contralateral breast cancers developed during the second decade in 5 patients, with a cumulative risk of 6.5% at 20 years. Significant treatment-related problems appeared during the second decade in 5 patients, including one chest wall sarcoma; all of these patients had received at least 60 Gy to breast and regional nodal areas. A comparison of these results with those in the literature allowed the following conclusions to be drawn: (a) the risk of death, as well as breast cancer mortality during the second decade, are similar for both conservatively and radically treated patients with Stage I and II breast cancer; (b) the risk of contralateral breast cancer is not greater than that observed following primary radical surgery without radiation therapy; (c) ipsilateral breast "recurrences" continue to occur at about 1% per year during the second decade. Such late recurrences are highly operable and have a favorable prognosis; (d) late progression of treatment-related sequelae is uncommon. This analysis supports the continued use of breast-conserving surgery with radiation therapy in the treatment of Stage I and II breast cancer.

Avoidance of treatment interruption: an unrecognized benefit of accelerated radiotherapy in oropharyngeal carcinomas?

PURPOSE: To assess the impact of treatment interruption on the potential gain in locoregional control obtained with accelerated radiotherapy (RT) compared with conventionally fractionated RT in patients with oropharyngeal carcinomas. METHODS AND MATERIALS: 152 patients treated with radical RT for oropharyngeal carcinomas between 1979 and 1996 were retrospectively analyzed. According to the American Joint Committee on Cancer (AJCC) staging system, there were 6/30/43/73 stages III/III/IV. Sixty-one patients were treated with a conventional RT schedule (median dose 70 Gy in 35 fractions), and 91 patients with either of two 5/5.5-week accelerated RT schedules (median dose 69.6-69.9 Gy in 41 fractions). Discounting weekends, RT was interrupted for 2 consecutive days or more in 53 patients (median duration 11 days, range 2-97), including 67% of the patients in the conventional RT group and 13% in the accelerated RT group. Median follow-up for surviving patients was 55 months (range 23-230). The Cox proportional hazards model was used for the multivariate analysis of factors influencing locoregional control. RESULTS: In univariate analysis, factors associated with a significant decrease in locoregional control included WHO performance status > or =1, advanced AJCC stages (III and IV), conventional RT fractionation, overall treatment time > or =44 days (median), and RT interruption. In the multivariate analysis, when introduced into the model individually, the three significant therapeutic factors remained significant after adjustment for the forced clinical variables. However, when the three therapeutic factors were introduced together into the model, beside the AJCC stage (P = 0.017), only RT interruption remained a significant independent adverse prognostic factor (P = 0.026). CONCLUSIONS: This multivariate analysis highlights the potential negative impact of treatment gaps on locoregional control in oropharyngeal carcinomas. This suggests that treatment interruption may be an even more important parameter than the type of RT schedule per se. Thus, when assessing the relative merit of two RT schedules, inclusion of the other therapeutic factors in a multivariate model is mandatory in order to avoid misinterpretation of the results.

Mammary recurrences in women younger than forty.

The crude mammary recurrence rate was studied in 5-year age intervals for 1,382 Stage I and II breast cancer patients treated by conservative surgery and radiation therapy and followed for a median of 11 years. Patients younger than 40 had a significantly higher local recurrence rate (41/210, 19%) than did older patients (106/1172, 9%). The majority of excess recurrences in the younger patients occurred early, with recurrence rates between 5 and 10 years being equal for the 2 age groups. A comparison of the clinical characteristics of the patient groups yielded no obvious explanation for the higher local recurrence rate in the younger patients, and 15-year cancer-specific survival was identical. Within the younger age group, recurrence rate was independent of clinical tumor size, and was unaffected by adjuvant treatment. Young patients with positive axillary nodes or negative hormone receptors appear to be at particularly high risk for mammary failure. Despite this apparent correlation with biologic aggressiveness, the 41 patients with mammary recurrence experienced long-term survival from time of primary treatment which was not significantly worse than that of patients not having had local recurrence. For 37 patients with operable mammary recurrence, the 10-year survival from time of salvage surgery was 64%.