Hypofractionated and accelerated radiotherapy with subcutaneous amifostine cytoprotection as short adjuvant regimen after breast-conserving surgery: interim report

Hypoxia and anaerobic metabolism relate with immunologically cold breast cancer and poor prognosis

PURPOSE

Hypoxia-Inducible Factor HIF1α and lactate dehydrogenase LDHA drive anaerobic tumor metabolism and define clinical aggressiveness. We investigated their expression in breast cancer and their role in immune response and prognosis of breast cancer.

METHODS

Tissue material from 175 breast cancer patients treated in a prospective study were analyzed with immunohistochemistry for HIF1α and LDH5 expression, in parallel with the tumor-infiltrating lymphocyte TIL-density and tertiary lymphoid structure TLS-density.

RESULTS

High LDH5 expression was noted in 48/175 tumors, and this was related to HIF1α overexpression (p < 0.0001), triple-negative TNBC histology (p = 0.01), poor disease-specific survival (p < 0.007), metastasis (p < 0.01), and locoregional recurrence (p = 0.03). High HIF1α expression, noted in 39/175 cases, was linked with low steroid receptor expression (p < 0.05), her2 overexpression (p = 0.01), poor survival (p < 0.04), and high metastasis rates (p < 0.004). High TIL-density in the invading tumor front (TILinv) was linked with low LDH5 and HIF expression (p < 0.0001) and better prognosis (p < 0.02). High TIL-density in inner tumor areas (TILinn) was significantly linked with TNBC. Multivariate analysis showed that PgR-status (p = 0.003, HR 2.99, 95% CI 1.4-6.0), TILinv (p = 0.02, HR 2.31, 95% CI 1.1-4.8), LDH5 (p = 0.01, HR 2.43, 95% CI 1.2-5.0), N-stage (p = 0.04, HR 2.42, 95% CI 1.0-5.8), T-stage (p = 0.04, HR 2.31, 95% CI 1.0-5.1), and her2 status (p = 0.05, HR 2.01, 95% CI 1.0-4.2) were independent variables defining death events.

CONCLUSION

Overexpression of LDH5, an event directly related to HIF1α overexpression, characterizes a third of breast tumors, which is more frequent in TNBC. Both HIF1α and LDH5 define cold breast cancer microenvironment and poor prognosis. A rational is provided to study further whether metabolic manipulations targeting HIF and LDH5 may enhance the antitumor immune response in breast cancer.

Long-Term Results of Postoperative Hypofractionated Accelerated Breast and Lymph Node Radiotherapy (HypoAR) with Hypofractionated Boost

We report long-term results (median follow-up 12 years) of hypofractionated accelerated radiotherapy (HypoAR) in patients treated with breast-conserving surgery. In total, 367 women were treated with HypoAR. Axillary and supraclavicular area (ASA) were treated in patients with involved nodes. In total, 290 patients (scheme A) received 3.5 Gy/day ×10 fractions (breast/ASA) followed by two 4 Gy fractions with electrons to the affected breast quadrant within 16 days. In total, 77 patients (Scheme B) received 2.7 Gy/day for 16 consecutive fractions (breast/ASA) within 22 days, while concurrently, the affected breast quadrant received an electron booster dose of 0.8 Gy for the first 13 fractions. Amifostine was offered to 252/367 patients. Early radiation toxicity was minimal. Regarding late toxicities, symptomatic breast edema was noted in 2.2%, asymptomatic breast fibrosis in 1.9%, and arm lymphedema in 3.7% of patients. Amifostine reduced early radiation dermatitis (p = 0.001). In total, 2.2% of patients developed contralateral breast and 1.6% other carcinomas. Locoregional recurrence (LR) occurred in 3.1% of patients (0% for in situ carcinomas). Positive margins after surgery, extracapsular node invasion, and HER2-enriched/triple-negative tumors were linked with significantly worse LR-free survival. The involvement of more than three nodes and luminal type other than A were independent prognostic variables of metastasis and death events. HypoAR delivering a biological dose of 50–52 Gy to the breast/ASA is a safe and effective therapy for patients treated with conservative surgery. The risk of carcinogenesis is low. Positive surgical margins, extracapsular node invasion, and HER2-enriched/triple-negative phenotypes appear as a cluster of features linked with a higher risk for locoregional relapse.

Use of Amifostine for Cytoprotection during Radiation Therapy: A Review

BACKGROUND

Radiation therapy is a cornerstone of the therapeutic modalities used in modern oncology. However, it is sometimes limited in its ability to achieve optimal tumor control by radiation-induced normal tissue toxicity. In delivering radiation therapy, a balance must be achieved between maximizing the dose to the tumor and minimizing any injury to the normal tissues. Amifostine was the first Food and Drug Administration (FDA)-approved clinical radiation protector intended to reduce the impact of radiation on normal tissue, lessening its toxicity and potentially allowing for increased tumor dose/control. Despite being FDA-approved almost 20 years ago, Amifostine has yet to achieve widespread clinical use.

SUMMARY

A thorough review of Amifostine's development, mechanism of action, and current clinical status were conducted. A brief history of Amifostine is given, from its development at Walter Reid Institute of Research to its approval for clinical use. The mechanism of action of Amifostine is explored. The results of a complete literature review of all prospective randomized trials to date involving the use of Amifostine in radiation therapy are presented. The results are arranged by treatment site and salient findings discussed. Side effects and complications to consider in using Amifostine are reviewed. Key Messages: Amifostine has been explored as a radiation protectant in most radiation treatment sites. Studies have demonstrated efficacy of Amifostine in all treatment sites reviewed, but results are heterogeneous. The heterogeneity of studies looking at Amifostine as a clinical radiation protectant has precluded a definitive answer on its efficacy. Complicating its clinical use is its toxicity and delivery requirements. Amifostine has largely fallen out of use with the advent of intensity modulated radiation therapy (IMRT). However, side effects with IMRT remain a challenge and concern. The use of Amifostine in the IMRT era has been poorly explored and is worthy of future study.

Expanding the therapeutic index of radiation therapy by normal tissue protection

Normal tissue damages induced by radiation therapy remain dose-limiting factors in radiation oncology and this is still true despite recent advances in treatment planning and delivery of image-guided radiation therapy. Additionally, as the number of long-term cancer survivors increases, unacceptable complications emerge and dramatically reduce the patients' quality of life. This means that patients and clinicians expect discovery of new options for the therapeutic management of radiation-induced complications. Over the past four decades, research has enhanced our understanding of the pathophysiological, cellular and molecular processes governing normal tissue toxicity. Those processes are complex and involve the cross-talk between the various cells of a tissue, including fibroblasts, endothelial, immune and epithelial cells as well as soluble paracrine factors including growth factors and proteases. We will review the translatable pharmacological approaches that have been developed to prevent, mitigate, or reverse radiation injuries based upon the targeting of cellular and signalling pathways. We will summarize the different steps of the research strategy, from the definition of initial biological hypotheses to preclinical studies and clinical translation. We will also see how novel research and therapeutic hypotheses emerge along the way as well as briefly highlight innovative approaches based upon novel radiotherapy delivery procedures.

ACCELERATED REGIMENS OF ADJUVANT RADIOTHERAPY IN THE TREATMENT OF BREAST CANCER

Treatment of breast cancer (BC) is a complex multidisciplinary problem. Often, radiation therapy is an obligatory component of treatment of breast cancer patients. Numerous large randomized trials have proved the efficacy of adjuvant radiotherapy in both the standard fractionation regimen in a single focal dose of 2 Gy to a total focal dose of 50 Gy for 25 fractions and in modes of hypofractionation using radiation exposure at a larger daily dose with a reduction in the total treatment time. The presented review summarizes the data of the largest studies on the modes of hypofractionation of postoperative radiotherapy for breast cancer. Most of the studies comparing the standard mode of fractionation of postoperative radiotherapy with the modes of hypofractionation showed comparable results for the main oncological parameters with similar tolerability, frequency of complications and good cosmetic results. It also shows the economic feasibility of applying accelerated regimes in everyday practice. Despite the fact that radiotherapy in the mode of hypofractionation has already become the standard of treatment and is recommended for use by the largest European and American cancer associations, indications for its conduct, the criteria for selection in the studies and the range of recommended single focal doses differ. The obtained results do not give an opportunity to confidently judge the advantage of one or another regime. It is necessary to determine the factors of a favorable and unfavorable prognosis, to clarify the indications for the use of various radiotherapy techniques. Therefore, questions about the optimal mode of hypo-fractionation of adjuvant radiotherapy, the timing of its initiation and the criteria for selecting patients for this type of therapy as part of the comprehensive treatment of breast cancer have not yet been fully resolved. Also open is the choice of optimal single and total doses of radiation, its combination with drug therapy.

Postmastectomy hypofractionated and accelerated radiation therapy with (and without) subcutaneous amifostine cytoprotection

PURPOSE

Postmastectomy radiation therapy (PMRT) provides major local control and survival benefits. More aggressive radiation therapy schemes may, however, be necessary in specific subgroups, provided they are safely administered. We report the tolerance and efficacy of a highly accelerated and hypofractionated regimen (HypoARC).

METHODS AND MATERIALS

One hundred twelve high-risk patients who had undergone mastectomy received 10 consecutive fractions of 3.5 Gy in 12 days (thoracic wall and axillary/supraclavicular areas). Two consecutive additional fractions of 4 Gy were given to the surgical scar area (electrons 8-10 MeV) and 1 3.5-Gy fraction to the axilla (in cases with extensive nodal involvement). A minimum follow-up of 24 months (median, 44 months) was allowed before analysis. Of 112 patients, 21 (18.7%) refused to receive amifostine, the remaining receiving tolerance-based individualized doses (500-1000 mg/day subcutaneously).

RESULTS

By use of a dose individualization algorithm, 68.1%, 11%, and 18.7% of patients received 1000 mg, 750 mg, and 500 mg/day of amifostine. Patchy moist skin desquamation outside and inside the booster fields was noted in 14 of 112 (12.5%) and 26 of 112 (23.2%) patients, respectively. No case of acute pneumonitis was recorded. High amifostine dose offered a significant skin protection. Within a median follow-up time of 44 months, moderate subcutaneous edema outside and within the booster thoracic area was noted in 5 of 112 (4.4%) and 8 of 112 (7.1%) cases, respectively. Intense asymptomatic radiographic findings of in field lung fibrosis were noted in 4 of 112 (3.6%) patients. Amifostine showed a significant protection against lung and soft tissue fibrosis. A 97% projected 5-year local relapse free survival and 84% 5-year disease-specific survival were recorded. Lack of steroid receptor expression, simple human epidermal growth factor 2 positivity, or triple negative phenotype defined higher metastasis rates but had no effect on local control.

CONCLUSIONS

PMRT with HypoARC showed an excellent early and short-term late toxicity profile, and amifostine further reduced early and late radiation sequelae. Encouraging local control rates are obtained in high-risk subgroups.

Assessment of contralateral mammary gland dose in the treatment of breast cancer using accelerated hypofractionated radiotherapy

AIM: To measure the dose distribution, related to the treatment planning calculations, in the contralateral mammary gland of breast cancer patients treated with accelerated hypofractionated 3-dimensional conformal radiotherapy.

METHODS: Thirty-four prospectively selected female patients with right breast cancer (pN0, negative surgical margins) were treated with breast-conserving surgery. A total dose of 42.5 Gy (2.66 Gy/fraction) was prescribed; it was requested that planning target volumes be covered by the 95% isodose line. The contralateral mammary gland was defined on CT simulation. The dose received was evaluated by dose volume histograms.

RESULTS: The measured contralateral breast doses were: (1) Dose maximum: 290-448 cGy [Equivalent (Eq) 337-522 cGy]; (2) Mean dose: 45-70 cGy (Eq 524-815 cGy); and (3) Median dose: 29-47 cGy (337-547 cGy) for total primary breast dose of 42.5 Gy in 16 equal fractions. The spearman rho correlation showed statistical significance between the contralateral breast volume and maximum dose (P = 0.0292), as well as mean dose (P = 0.0025) and median dose (P = 0.046) to the breast.

CONCLUSION: Minimizing the dose to the contralateral breast has to be one of the priorities of the radiation oncologist when using short schedules because of the radiosensitivity of this organ at risk. Further study is necessary to assess the long-term clinical impact of this schedule.

Amifostine-related fever-rash during fractionated radiotherapy: diagnostic and predictive role of C-reactive protein

INTRODUCTION

Fever/rash is a side-effect of amifostine that demands immediate interruption of the drug. Here, we focus on the role of C-reactive protein (CRP) as a putative marker linked with amifostine fever/rash.

MATERIALS AND METHODS

The CRP serum values were analyzed in 496 patients receiving radiotherapy supported with amifostine (500-1000 mg/d). CRP levels were recorded before the onset of radiotherapy (day 0), on day 15 and when the fever/rash appeared. For 121 out of 496 patients, CRP values on day 7 were also available. About 79 patients (15.9%) developed fever/rash symptoms.

RESULTS

The CRP levels before the onset of therapy were 0 to 20.7 mg/dL (normal, ≤0.5 mg/dL). For patients who did not develop fever/rash, the CRP levels increased from a median of 0.30 to 0.50 on day 15; P = 0.001. Patients who developed fever/rash showed a more than 7-fold increase of the median CRP levels (median, 3.50; P < 0.0001). This sharp CRP rise was specific for amifostine-related fever/rash. Initially abnormal CRP levels were linked with a 2-fold risk for fever/rash (P = 0.01), while abnormal levels on day 7 were linked with a 3-fold higher risk (P = 0.08). The occurrence of fever/rash was independent of the amifostine dose level.

CONCLUSIONS

Sharp rise of CRP levels on the day after the fever/rash development suggest amifostine-related etiology of fever/rash. Abnormal initial CRP levels and/or high CRP levels on day 7 should be considered as an alert signal as the probability to develop fever/rash reaches the 30%.