Chemoradiation schedules--what radiotherapy?

High-dose accelerated hypofractionated three-dimensional conformal radiotherapy (at 3 Gy/fraction) with concurrent vinorelbine and carboplatin chemotherapy in locally advanced non-small-cell lung cancer: a feasibility study

Background

Increasing the radiotherapy dose can result in improved local control for non-small-cell lung cancer (NSCLC) and can thereby improve survival. Accelerated hypofractionated radiotherapy can expose tumors to a high dose of radiation in a short period of time, but the optimal treatment regimen remains unclear. The purpose of this study was to evaluate the feasibility of utilizing high-dose accelerated hypofractionated three-dimensional conformal radiotherapy (at 3 Gy/fraction) with concurrent vinorelbine (NVB) and carboplatin (CBP) chemotherapy for the treatment of local advanced NSCLC.

Methods

Untreated patients with unresectable stage IIIA/IIIB NSCLC or patients with a recurrence of NSCLC received accelerated hypofractionated three-dimensional conformal radiotherapy. The total dose was greater than or equal to 60 Gy. The accelerated hypofractionated radiotherapy was conducted once daily at 3 Gy/fraction with 5 fractions per week, and the radiotherapy was completed in 5 weeks. In addition to radiotherapy, the patients also received at least 1 cycle of a concurrent two-drug chemotherapy regimen of NVB and CBP.

Results

A total of 26 patients (19 previously untreated cases and 7 cases of recurrent disease) received 60Gy-75Gy radiotherapy with concurrent chemotherapy. All of the patients underwent evaluations for toxicity and preliminary therapeutic efficacy. There were no treatment-related deaths within the entire patient group. The major acute adverse reactions were radiation esophagitis (88.5%) and radiation pneumonitis (42.3%). The percentages of grade III acute radiation esophagitis and grade III radiation pneumonitis were 15.4% and 7.7%, respectively. Hematological toxicities were common and did not significantly affect the implementation of chemoradiotherapy after supportive treatment. Two patients received high dose of 75 Gy had grade III late esophageal toxicity, and none had grade IV and above. Grade III and above late lung toxicity did not occur.

Conclusion

High-dose accelerated hypofractionated three-dimensional conformal radiotherapy with a dose of 60 Gy or greater with concurrent NVB and CBP chemotherapy might be feasible. However esophagus toxicity needs special attention. A phase I trial is recommended to obtain the maximum tolerated radiation dose of accelerated hypofractionated radiotherapy with concurrent chemotherapy.

Radiosensitization of brain metastasis by targeting c-MET

Radiotherapy is the most widely used therapeutic modality in brain metastasis; however, it only provides palliation due to inevitable tumor recurrence. Resistance of tumor cells to ionizing radiation is a major cause of treatment failure. A critical unmet need in oncology is to develop rationale driven approaches that can enhance the efficacy of radiotherapy against metastatic tumor. Utilizing in vivo orthotopic primary tumor and brain metastasis models that recapitulate clinical situation of the patients with metastatic breast cancer, we investigated a molecular mechanism through which metastatic tumor cells acquire resistance to radiation. Recent studies have demonstrated that the hepatocyte growth factor (HGF)-c-Met pathway is essential for the pathologic development and progression of many human cancers such as proliferation, invasion and resistance to anticancer therapies. In this study, c-Met signaling activity as well as total c-Met expression was significantly upregulated in both breast cancer cell lines irradiated in vitro and ex vivo radio-resistant cells derived from breast cancer brain metastatic xenografts. To interrogate the role of c-Met signaling in radioresistance of brain metastasis, we evaluated the effects on tumor cell viability, clonogenicity, sensitivity to radiation, and in vitro/in vivo tumor growth after targeting c-Met by small-hairpin RNA (shRNA) or small-molecule kinase inhibitor (PF-2341066). Although c-Met silencing or radiation alone demonstrated a modest decrease in clonogenic growth of parental breast cancers and brain metastatic derivatives, combination of two modalities showed synergistic antitumor effects resulting in significant prolongation of overall survival in tumor-bearing mice. Taken together, optimizing c-Met targeting in combination with radiation is critical to enhance the effectiveness of radiotherapy in the treatments of brain metastasis.

Radiochemotherapy in locally advanced squamous cell carcinomas of the head and neck

Squamous cell carcinoma of the head and neck (SCCHN) is a common disease that develops in the upper aerodigestive epithelium. The most important risk factors are tobacco and alcohol consumption. There is also increasing evidence that human papillomavirus plays an important role in the cause of SCCHN. The complex anatomy, the vital functions of the upper aerodigestive tract and the close proximity to vital structures, explain that the goal of treatment is not only to improve survival outcomes, but also to preserve organ function. Radiotherapy and surgery are the standard modalities of treatment, reflecting the locoregional predominance of SCCHN. Chemotherapy plays an important role in the treatment of patients with locoregionally advanced disease, in conjunction with radiotherapy and surgery. Indeed, standard therapy for resectable locoregionally advanced (stage III or IV) SCCHN cancers consists either of surgery and adjuvant chemoradiotherapy or definitive concomitant chemoradiotherapy, depending upon disease site, stage and resectability of the tumour, or institutional experience. Concomitant chemoradiotherapy has been shown in several randomised trials to improve disease-free and overall survival in the postoperative setting for resected disease with poor prognostic factors. Furthermore, multiple randomised studies and meta-analyses have shown that definitive chemoradiotherapy, as well anti-epidermal growth factor receptor treatment in one randomised study, improved disease-free and overall survival when compared with radiotherapy alone. This overview reviews the most relevant published studies on the multidisciplinary management of SCCHN and discusses future strategies to reduce locoregional failures.

Optimal surgery time after preoperative chemoradiotherapy for locally advanced rectal cancers

OBJECTIVE

To evaluate the effect of the time interval between chemoradiotherapy (CRT) and surgery on CRT response and surgical outcomes.

SUMMARY BACKGROUND DATA

Although preoperative CRT is a standard component of multimodal treatment for locally advanced rectal cancers, the optimal time for surgery after CRT has yet to be established. This study analyzed outcomes in 397 prospectively enrolled patients with locally advanced rectal cancer who underwent fractionated CRT involving 50.4 Gy radiotherapy followed by surgical resection between 4 and 8 weeks later.

METHODS

Patients were divided into 2 groups according to the time that elapsed between CRT and surgery: group A (28-41 day interval) and group B (42-56 day interval). CRT responses and surgical outcomes were analyzed.

RESULTS

Of the 397 patients, 217 (54.7%) were in group A and 180 (45.3%) in group B. The 2 groups were similar in terms of pretreatment characteristics other than a slight difference in mean age (A: 55.3 years vs. B: 57.5 years, P = 0.042). Analysis of CRT responses showed that the 2 groups were similar in terms of T-level downstaging rate (A: 47.5% vs. B: 44.4%, P = 0.548), volume reduction rate (A: 34.6% vs. B: 34.2%, P = 0.870) and complete response rate (A: 13.8% vs. B: 15.0%, P = 0.740). Analysis of surgical outcomes showed that the 2 groups were also similar in terms of sphincter-preservation rate (A: 83.9% vs. B: 82.2%, P = 0.688) and anastomosis-related complication rate (A: 5.5% vs. B: 3.9%, P = 0.453). The median follow-up period was 31 months (range, 5-63), and both groups showed similar local recurrence-free survival rates (P = 0.1165).

CONCLUSION

The present findings suggest that compared with a 4 to 6 week interval, delaying surgery for 6 to 8 weeks after completion of fractionated radiotherapy with concurrent chemotherapy does not improve CRT response or the sphincter-preservation rate, and does not decrease morbidity or local recurrence.

Comparison of two fractionation regimens in the multimodal therapy of cancer of the esophagus

Multimodal therapy is increasingly utilized in the management of esophageal cancer. The optimum dose and fraction is unclear, and this retrospective analysis compared two radiation regimens in multimodality regimens where the chemotherapy arm and the type and magnitude of surgery was constant. Ninety-three consecutive patients with squamous cell carcinoma or adenocarcinoma of the esophagus were reviewed. Forty patients received the conventional unit regimen of 44 Gy in 22 daily fractions (2 Gy/fraction), and 40 patients received an increased dose per fraction (40 Gy in 15 daily fractions [2.67 Gy/fraction]). All patients received two courses of 5-fluorouracil and cisplatin and surgery was carried out within 8 weeks of completing therapy. The median overall survival in the group receiving the increased dose per fraction group was 25 months compared with 17 months in the conventional dose per fraction group (P=0.08). At 1, 3, and 5 years, 66%, 38%, and 38%, of patients in the increased dose per fraction group were alive, compared with 65%, 18%, and 15% in the conventional dose per fraction group (P=0.13), respectively. In the conventional dose per fraction group, two patients developed esophageal fistulae and one patient died postoperatively due to hemorrhage from an aorto-enteric fistula. There were no significant differences observed between treatment groups, but a trend toward improved efficacy appeared with the increased dose per fraction.

Acute tumor vascular effects following fractionated radiotherapy in human lung cancer: In vivo whole tumor assessment using volumetric perfusion computed tomography

PURPOSE

To quantitatively assess the in vivo acute vascular effects of fractionated radiotherapy for human non-small-cell lung cancer using volumetric perfusion computed tomography (CT).

METHODS AND MATERIALS

Sixteen patients with advanced non-small-cell lung cancer, undergoing palliative radiotherapy delivering 27 Gy in 6 fractions over 3 weeks, were scanned before treatment, and after the second (9 Gy), fourth (18 Gy), and sixth (27 Gy) radiation fraction. Using 16-detector CT, multiple sequential volumetric acquisitions were acquired after intravenous contrast agent injection. Measurements of vascular blood volume and permeability for the whole tumor volume were obtained. Vascular changes at the tumor periphery and center were also measured.

RESULTS

At baseline, lung tumor vascularity was spatially heterogeneous with the tumor rim showing a higher vascular blood volume and permeability than the center. After the second, fourth, and sixth fractions of radiotherapy, vascular blood volume increased by 31.6% (paired t test, p = 0.10), 49.3% (p = 0.034), and 44.6% (p = 0.0012) respectively at the tumor rim, and 16.4% (p = 0.29), 19.9% (p = 0.029), and 4.0% (p = 0.0050) respectively at the center of the tumor. After the second, fourth, and sixth fractions of radiotherapy, vessel permeability increased by 18.4% (p = 0.022), 44.8% (p = 0.0048), and 20.5% (p = 0.25) at the tumor rim. The increase in permeability at the tumor center was not significant after radiotherapy.

CONCLUSION

Fractionated radiotherapy increases tumor vascular blood volume and permeability in human non-small-cell lung cancer. We have established the spatial distribution of vascular changes after radiotherapy; greater vascular changes were demonstrated at the tumor rim compared with the center.

Alternating Chemotherapy and Radiotherapy in Locally Advanced Head and Neck Cancer: An Alternative?

Rapidly alternating chemotherapy and radiotherapy (ACR) is a minor variation of concurrent chemoradiation (CCR). This scheduling has been tested in advanced head and neck cancer and has shown superiority over standard radiation in some randomized trials with only marginally greater toxicity. This paper reviews ACR in advanced head and neck cancer. The hypothesis that this approach could have a better toxicity profile than CCR is discussed in light of the published clinical data. Efficacy is also discussed on the basis of available phase III trials. Published data indicate that rapidly alternating chemoradiation adds to toxicity less than CCR and results in comparable 3-year overall survival rates. In conclusion, ACR could be as active as, and possibly less toxic than, CCR. Comparative trials are highly recommended.

Indications for neoadjuvant long-term radiotherapy

If radiotherapy is considered in the management of a rectal cancer, there is very strong evidence supporting preoperative settings. To avoid treatment to cases where surgery alone is enough, exact preoperative staging with MRI is crucial.

Radiochemotherapy in rectal cancer: the role of oxaliplatin

Radiation therapy is well established in the treatment of early and locally advanced rectal cancer, where it has been used in both the pre-operative and postoperative settings. Pre-operatively, radiation therapy has been shown in a series of studies culminating in the Dutch total mesorectal excision (TME) study to significantly reduce the rate of local recurrence at 2 years. However, the overall rate of survival was not improved in this study because radiotherapy failed to reduce the incidence of distant metastases. Chemotherapy, however, may reduce distant metastatic spread, as well as increasing the rate of R0 resectability and sphincter-saving surgery when used in combination with radiotherapy in the neoadjuvant setting. Oxaliplatin is a prime candidate for radiochemotherapy in rectal cancer because it frequently has large and rapid cytoreductive effects in colorectal malignancies and has been shown in vitro and preclinical models to be radiosensitizing. In an Italian phase I/II study, weekly oxaliplatin combined with standard infusional 5-FU and pre-operative radiotherapy has shown low toxicity and promising antitumour activity. These encouraging results are now being followed up in a more extensive trials programme. A randomized trial comparing this regimen with standard infusional FUra and radiotherapy (STAR, Studio nazonaleTerapia neoAdiuvante Retto [National Study on Neoadjuvant Treatment of Rectal cancer]) is being launched in Italy. A new phase II study, CORE (Capecitabine, Oxaliplatin, Radiotherapy and Excision), is now in development in Europe and will use a similar weekly treatment regimen with an oral fluropyrimidine in place of infusional FUra, and a number of further oxaliplatin-based radiochemotherapy studies in rectal cancer are planned or in progress. In summary, radiochemotherapy appears to have the potential to significantly improve clinical outcomes in rectal cancer, and oxaliplatin-based treatment is proving central to its ongoing development.