Jacques Borger

Risk factors in breast-conservation therapy.

PURPOSE To identify clinical and pathologic factors associated with an increased risk of local recurrence following breast-conservation therapy (BCT) to assess the safety of this procedure for all subgroups of patients. PATIENTS AND METHODS The study population consisted of 1,026 patients with clinical stage I and II breast cancer treated between 1979 and 1988 at the Netherlands Cancer Institute. The BCT regimen consisted of local excision and axillary lymph node dissection (ALND) followed by whole-breast irradiation to a total dose of 50 Gy in 2-Gy fractions and boost irradiation (mostly by iridium implant) of 15 to 25 Gy. RESULTS With a median follow-up duration of 66 months, the actuarial breast recurrence rate was 4% at 5 years, counting all breast recurrences. Univariate analysis showed seven factors to be associated with an increased risk of local recurrence; age, residual tumor at reexcision, histologic tumor type, presence of any carcinoma-in-situ component, vascular invasion, microscopic margin involvement, and whole-breast radiation dose. Three factors remained independently significant after proportional hazard regression analysis: age, margin involvement, and the presence of vascular invasion. When the analysis was repeated, but counting only those breast recurrences that occurred before regional or distant failures, only young age and vascular invasion were independent predictive factors. In the third analysis, factors predicting the necessity of local salvage treatment were analyzed. In this analysis, the possible bias in the former analysis caused by censoring actuarial methods was avoided. The results were the same as in the second analysis, showing young age and vascular invasion as the only independent predictive factors. Breast recurrence rates were 6% for patients less than 40 years of age and 8% for patients with tumors showing vascular invasion. In the absence of risk factors, the breast recurrence rate is only 1% at 5 years. CONCLUSION Slightly higher recurrence rates were found in patients less than 40 years of age and in patients with tumors showing vascular invasion. The role of margin involvement is uncertain.

Randomised trial of high-dose chemotherapy and haemopoietic progenitor-cell support in operable breast cancer with extensive axillary lymph-node involvement

BACKGROUND Uncontrolled studies suggest that high-dose chemotherapy is beneficial in patients with breast cancer and multiple metastases to the axillary lymph nodes. Many physicians accept this treatment as standard care. We aimed to assess adjuvant high-dose chemotherapy in breast cancer in a phase II randomised trial. METHODS 97 women aged younger than 60 years, who had breast cancer with extensive axillary-node metastases (confirmed by a tumour-positive infraclavicular lymph-node biopsy), received three courses of up-front chemotherapy (FE120C). This regimen consisted of cyclophosphamide 500 mg/m2, epirubicin 120 mg/m2, and 5-fluorouracil 500 mg/m2 once weekly for 3 weeks. After surgery, stable patients or those who responded to chemotherapy were randomly assigned conventional therapy (fourth course of FE120C, followed by radiation therapy and 2 years of tamoxifen [40 patients]) or high-dose therapy (identical treatment but an additional high-dose regimen and peripheral-blood progenitor-cell [PBPC] support after the fourth FE120C course [41 patients]). This high-dose regimen comprised cyclophosphamide 6 g/m2, thiotepa 480 mg/m2, and carboplatin 1600 mg/m2. The primary endpoint was overall and disease-free survival. All analyses were by intention to treat. FINDINGS No patients died from toxic effects of chemotherapy. With a median follow-up of 49 (range 21-76) months, the 4-year overall and relapse-free survivals for all 97 patients were 75% and 54%, respectively. There was no significant difference in survival between the patients on conventional therapy and those on high-dose therapy. INTERPRETATION High-dose therapy is associated with substantial cost and acute toxic effects, but also has potentially irreversible long-term effects. Until the benefit of this therapy is substantiated by large-scale phase III trials, high-dose chemotherapy should not be used in the adjuvant treatment of breast cancer, apart from in randomised studies.

The Impact of tumor size and histology on local control after breast-conserving therapy

To investigate possible contraindications for breast-conserving therapy (BCT) a retrospective clinicopathological study was carried out in 585 patients treated conservatively in The Netherlands Cancer Institute from 1979 to 1984. The local recurrence rate in the breast was 2% at 6 years and was similar in stages I and II breast cancer. Invasive cancer with extensive ductal carcinoma in situ (DCIS) component appeared to be the only main prognostic factor when local failure in the breast was considered. A multivariate analysis revealed that tumor size, microscopically incomplete excision of the primary tumor and age did not have a significant influence on local control alone, when this was corrected for extensive DCIS. When breast and axillary recurrences were taken together, age and extensive DCIS component appeared to be two independent prognostic factors according to a multivariate analysis. Especially patients younger than 40 years with an extensive DCIS component had a higher locoregional recurrence rate.

Cardiac and lung complication probabilities after breast cancer irradiation

PURPOSE To assess for locoregional irradiation of breast cancer patients, the dependence of cardiac (cardiac mortality) and lung (radiation pneumonitis) complications on treatment technique and individual patient anatomy. MATERIALS AND METHODS Three-dimensional treatment planning was performed for 30 patients with left-sided breast cancer and various breast sizes. Two locoregional techniques (Techniques A and B) and a tangential field technique, including only the breast in the target volume, were planned and evaluated for each patient. In both locoregional techniques tangential photon fields were used to irradiate the breast. The internal mammary (IM)-medial supraclavicular (MS) lymph nodes were treated with an anterior mixed electron/photon field (Technique A) or with an obliquely incident mixed electron/photon IM field and an anterior electron/photon MS field (Technique B). The optimal IM and MS electron field dimensions and energies were chosen on the basis of the IM-MS lymph node target volume as delineated on CT-slices. The position of the tangential fields was adapted to match the IM-MS fields. Dose-volume histograms (DVHs) and normal tissue complication probabilities (NTCPs) for the heart and lung were compared for the three techniques. In the beams eye view of the medial tangential fields the maximum distance of the heart contour to the posterior field border was measured; this value was scored as the Maximum Heart Distance. RESULTS The lymph node target volume receiving more than 85% of the prescribed dose was on average 99% for both locoregional irradiation techniques. The breast PTV receiving more than 95% of the prescribed dose was generally smaller using Technique A (mean: 90%, range: 69-99%) than using Technique B (mean: 98%, range: 82-100%) or for the tangential field technique (mean: 98%, range: 91-100%). NTCP values for excess cardiac mortality due to acute myocardial ischemia varied considerably between patients, with minimum and maximum values of 0.1 and 7.5% (Technique A), 0.1 and 5.8% (Technique B) and 0.0 and 6.1% (tangential tech.). The NTCP values were on average significantly higher (P<0.001) by 1.7% (Technique A) and 1.0% (Technique B) when locoregional breast irradiation was given, compared with irradiation of the left breast only. The NTCP values for the tangential field technique could be estimated using the Maximum Heart Distance. NTCP values for radiation pneumonitis were very low for all techniques; between 0.0 and 1.0%. CONCLUSIONS Technique B results in a good coverage of the breast and locoregional lymph nodes, while Technique A sometimes results in an underdosage of part of the target volume. Both techniques result in a higher probability of heart complications compared with tangential irradiation of the breast only. Irradiation toxicity for the lung is low in all techniques. The Maximum Heart Distance is a simple and useful parameter to estimate the NTCP values for cardiac mortality for tangential breast irradiation.

Mammographically detected ductal carcinoma in situ of the breast treated with breast-conserving surgery and definitive breast irradiation: long-term outcome and prognostic significance of patient age and margin status

PURPOSE This study was performed to determine the long-term outcome for women with mammographically detected ductal carcinoma in situ (DCIS; intraductal carcinoma) of the breast treated with breast-conserving surgery followed by definitive breast irradiation. METHODS AND MATERIALS An analysis was performed of 422 mammographically detected intraductal breast carcinomas in 418 women from 11 institutions in North America and Europe. All patients were treated with breast-conserving surgery followed by definitive breast irradiation. The median follow-up time was 9.4 years (mean, 9.4 years; range, 0.1-19.8 years). RESULTS The 15-year overall survival rate was 92%, and the 15-year cause-specific survival rate was 98%. The 15-year rate of freedom from distant metastases was 94%. There were 48 local failures in the treated breast, and the 15-year rate of any local failure was 16%. The median time to local failure was 5.0 years (mean, 5.7 years; range, 1.0-15.2 years). Patient age at the time of treatment and final pathology margin status from the primary tumor excision were both significantly associated with local failure. The 10-year rate of local failure was 31% for patient age < or = 39 years, 13% for age 40-49 years, 8% for age 50-59 years, and 6% for age > or = 60 years (p = 0.0001). The 10-year rate of local failure was 24% when the margins of resection were positive, 9% when the margins of resection were negative, 7% when the margins of resection were close, and 12% when the margins of resection were unknown (p = 0.030). Patient age < or = 39 years and positive margins of resection were both independently associated with an increased risk of local failure (p = 0.0006 and p = 0.023, respectively) in the multivariable Cox regression model. CONCLUSIONS The 15-year results from the present study demonstrated high rates of overall survival, cause-specific survival, and freedom from distant metastases following the treatment of mammographically detected ductal carcinoma in situ of the breast using breast-conserving surgery and definitive breast irradiation. Younger age and positive margins of resection were both independently associated with an increased risk of local failure. The 15-year results in the present study serve as an important benchmark for comparison with other treatment modalities. These results support the use of breast-conserving surgery and definitive breast irradiation for the treatment of appropriately selected patients with mammographically detected ductal carcinoma in situ of the breast.

Variability in target volume delineation on CT scans of the breast

PURPOSE To determine the intra- and interobserver variation in delineation of the target volume of breast tumors on computed tomography (CT) scans in order to perform conformal radiotherapy. MATERIALS AND METHODS The clinical target volume (CTV) of the breast was delineated in CT slices by four radiation oncologists on our clinically used delineation system. The palpable glandular breast tissue was marked with a lead wire on 6 patients before CT scanning, whereas 4 patients were scanned without a lead wire. The CTV was drawn by each observer on three separate occasions. Planning target volumes (PTVs) were constructed by expanding the CTV by 7 mm in each direction, except toward the skin. The deviation in the PTV extent from the average extent was quantified in each orthogonal direction for each patient to find a possible directional dependence in the observer variations. In addition, the standard deviation of the intra- and interobserver variation in the PTV volume was quantified. For each patient, the common volumes delineated by all observers and the smallest volume encompassing all PTVs were also calculated. RESULTS The patient-averaged deviations in PTV extent were larger in the posterior (42 mm), cranial (28 mm), and medial (24 mm) directions than in the anterior (6 mm), caudal (15 mm), and lateral (8 mm) directions. The mean intraobserver variation in volume percentage (5.5%, 1 SD) was much smaller than the interobserver variation (17.5%, 1 SD). The average ratio between the common and encompassing volume for the four observers separately was 0.82, 0.74, 0.82, and 0.80. A much lower combined average ratio of 0.43 was found because of the large interobserver variations. For the observer who placed the lead wire, the intraobserver variation in volume was decreased by a factor of 4 on scans made with a lead wire in comparison to scans made without a lead wire. For the other observers, no improvement was seen. Based on these results, an improved delineation protocol was designed. CONCLUSIONS Intra- and especially interobserver variation in the delineation of breast target volume on CT scans can be rather large. A detailed delineation protocol making use of CT scans with lead wires placed on the skin around the palpable breast by the delineating observer reduces the intraobserver variation. To reduce the interobserver variation, better imaging techniques and pathology studies relating glandular breast tissue to imaging may be needed to provide more information on the extent of the clinical target volume.

Mature Results of an Individualized Radiation Dose Prescription Study Based on Normal Tissue Constraints in Stages I to III Non-Small-Cell Lung Cancer

PURPOSE We previously showed that individualized radiation dose escalation based on normal tissue constraints would allow safe administration of high radiation doses with low complication rate. Here, we report the mature results of a prospective, single-arm study that used this individualized tolerable dose approach. PATIENTS AND METHODS In total, 166 patients with stage III or medically inoperable stage I to II non-small-cell lung cancer, WHO performance status 0 to 2, a forced expiratory volume at 1 second and diffusing capacity of lungs for carbon monoxide >or= 30% were included. Patients were irradiated using an individualized prescribed total tumor dose (TTD) based on normal tissue dose constraints (mean lung dose, 19 Gy; maximal spinal cord dose, 54 Gy) up to a maximal TTD of 79.2 Gy in 1.8 Gy fractions twice daily. Only sequential chemoradiation was administered. The primary end point was overall survival (OS), and the secondary end point was toxicity according to Common Terminology Criteria of Adverse Events (CTCAE) v3.0. RESULTS The median prescribed TTD was 64.8 Gy (standard deviation, +/- 11.4 Gy) delivered in 25 +/- 5.8 days. With a median follow-up of 31.6 months, the median OS was 21.0 months with a 1-year OS of 68.7% and a 2-year OS of 45.0%. Multivariable analysis showed that only a large gross tumor volume significantly decreased OS (P < .001). Both acute (grade 3, 21.1%; grade 4, 2.4%) and late toxicity (grade 3, 4.2%; grade 4, 1.8%) were acceptable. CONCLUSION Individualized prescribed radical radiotherapy based on normal tissue constraints with sequential chemoradiation shows survival rates that come close to results of concurrent chemoradiation schedules, with acceptable acute and late toxicity. A prospective randomized study is warranted to further investigate its efficacy.

Dose and volume effects on fibrosis after breast conservation therapy.

PURPOSE To analyze factors involved in the development of fibrosis in the boost area after breast conservation therapy (BCT) in patients treated with continuous low dose rate iridium implants following 50 Gy whole breast irradiation. METHODS AND MATERIALS Fibrosis was estimated by palpation in 404 patients by four physicians. The median follow-up (FUP) duration was 70 months (range 30-133 months). Original implant data were used for reconstruction and dose-volume calculations. The total dose of the external whole breast irradiation and iridium implants was expressed in Normalized Total Dose (NTD): the total dose given in fractions of 2 Gy, which is biologically equivalent to the actual dose given according to the linear-quadratic model, using an alpha/beta value of 2 Gy, and 1.5 h for the recovery half-life of sublethal damage repair. To identify predictors of fibrosis we used a proportional odds model in a polychotomous logistic regression analysis. RESULTS Seven independent factors were identified that were related to the severity of fibrosis: age, duration of FUP, clinical T-size, photon beam energy, NTD level, implant volume, and adjuvant chemotherapy. From the proportional odds model, a volume exponent could be estimated (0.16 +/- 0.04) that enabled us to determine dose-effect relations for different volumes. A 10-fold higher risk of fibrosis was seen when the total dose was above 79 Gy as compared with doses lower than 70 Gy. A fourfold increase in risk of fibrosis was seen for each 100 cm3 increase in irradiated boost volume. The use of adjuvant chemotherapy resulted in a twofold increase in the risk of fibrosis (dose modifying factor approximately 1.08). The application of Co-60 beams had a similar effect. The relative odds for the other factors were smaller (1.4 for each 10 years of older age, and 1.2 for clinical T-size over 20 mm). The FUP-period had a nonlinear effect: relative odds 2.2 at 6 years, 3.6 at 7-8 years, and 2.8 at 9-11 years. The dose rate (mean 0.57, range 0.26-0.89 Gy/h) had no influence on the development of fibrosis and there was no correlation between dose rate and irradiated volume. CONCLUSIONS To optimize cosmetic results after BCT, both the total dose and the irradiated volume should be kept as low as possible. Minimum effective dose levels still have to be established. The boost volume can be minimized by more conformal brachytherapy techniques and optimal localization. It may be worthwhile to take adjuvant chemotherapy into account in decisions on boost dose levels.

Validation of the methods of cosmetic assessment after breast-conserving therapy in the EORTC “boost versus no boost” trial

PURPOSE To evaluate both qualitative and quantitative scoring methods for the cosmetic result after breast-conserving therapy (BCT), and to compare the usefulness and reliability of these methods. METHODS AND MATERIALS In EORTC trial 22881/10882, stage I and II breast cancer patients were treated with tumorectomy and axillary dissection. A total of 5318 patients were randomized between no boost and a boost of 16 Gy following whole-breast irradiation of 50 Gy. The cosmetic result was assessed for 731 patients in two ways. A panel scored the qualitative appearance of the breast using photographs taken after surgery and 3 years later. Digitizer measurements of the displacement of the nipple were also made using these photographs in order to calculate the breast retraction assessment (BRA). The cosmetic results after 3-year follow-up were used to analyze the correlation between the panel evaluation and digitizer measurements. RESULTS For the panel evaluation the intraobserver agreement for the global cosmetic score as measured by the simple Kappa statistic was 0.42, considered moderate agreement. The multiple Kappa statistic for interobserver agreement for the global cosmetic score was 0.28, considered fair agreement. The specific cosmetic items scored by the panel were all significantly related to the global cosmetic score; breast size and shape influenced the global score most. For the digitizer measurements, the standard deviation from the average value of 30.0 mm was 2.3 mm (7.7%) for the intraobserver variability and 2.6 mm (8.7%) for the interobserver variability. The two methods were significantly, though moderately, correlated; some items scored by the panel were only correlated to the digitizer measurements if the tumor was not located in the inferior quadrant of the breast. CONCLUSIONS The intra- and interobserver variability of the digitizer evaluation of cosmesis was smaller than that of the panel evaluation. However, there are some treatment sequelae, such as disturbing scars and skin changes, that can not be evaluated by BRA measurements. Therefore, the methods of cosmetic evaluation used in a study must be chosen in a way that balances reliability and comprehensiveness.

Continuing Risk of Ipsilateral Breast Relapse After Breast-Conserving Therapy at Long-Term Follow-up

PURPOSE Currently, the local treatment of most patients with early invasive breast cancer consists of breast-conserving therapy (BCT). We have previously reported on the risk factors for ipsilateral breast relapse (IBR) in 1,026 patients treated with BCT after a median follow-up of 5.5 years. In the present study, we evaluated the IBR incidence and the risk factors for IBR after prolonged follow-up. METHODS AND MATERIALS We updated the disease outcome for all 1,026 patients using the clinical information collected from the medical registration of The Netherlands Cancer Institute and performed step-wise proportional hazard Cox regression analysis to identify the risk factors associated with an increased risk of IBR after BCT at long-term follow-up. RESULTS After a median follow-up of 13.3 years, 114 patients had developed an IBR as the first event. The IBR rate was 9.3% and 13.8%, respectively, at 10 and 15 years. Also, the increase in IBR was continuous without reaching a plateau, even after 15 years. Univariate analysis showed that involved surgical resection margins, young age, vascular invasion, and the presence and quantity of an in situ component are risk factors for IBR. Multivariate analysis showed that tumor-positive surgical resection margins (hazard ratio, 2.9; 95% confidence interval, 1.7-5.2, p = 0.0002) or the presence of vascular invasion (hazard ratio, 2.0; 95% confidence interval, 1.2-3.2, p = 0.004) is the major independent risk factor for IBR. CONCLUSIONS The data from long-term follow-up showed a constant increase in IBR among patients treated by BCT, even after 15 years, without reaching a plateau. Involved surgical resection margins and vascular invasion were the most important risk factors for IBR.