Phase II study of neoadjuvant therapy with docetaxel, cisplatin, panitumumab, and radiation therapy followed by surgery in patients with locally advanced adenocarcinoma of the distal esophagus (ACOSOG Z4051)

BACKGROUND

Preoperative chemoradiotherapy (CRT) improves outcomes in patients with locally advanced but resectable adenocarcinoma of the esophagus. ACOSOG Z4051 evaluated CRT with docetaxel, cisplatin, and panitumumab (DCP) in this patient group with a primary end point of a pathologic complete response (pCR) ≥35%.

PATIENTS AND METHODS

From 15 January 2009 to 22 July 2011, 70 patients with locally advanced but resectable distal esophageal adenocarcinoma were enrolled. Patients received docetaxel (40 mg/m(2)), cisplatin (40 mg/m(2)), and panitumumab (6 mg/kg) on weeks 1, 3, 5, 7, and 9 with RT (5040 cGy, 180 cGy/day × 28 days) beginning week 5. Resection was planned after completing CRT. PCR was defined as no viable residual tumor cells. Secondary objectives included near-pCR (≤10% viable cancer cells), toxicity, and overall and disease-free survival. Adverse events were graded using the CTCAE Version 3.0.

RESULTS

Five of 70 patients were ineligible. Of 65 eligible patients (59 M; median age 61), 11 did not undergo surgery, leaving 54 assessable. PCR rate was 33.3% and near-pCR was 20.4%. Secenty-three percent of patients completed DCP (n = 70) and 92% completed RT. 48.5% had toxicity ≥grade 4. Lymphopenia (43%) was most common. Operative mortality was 3.7%. Adult respiratory distress syndrome was encountered in two patients (3.7%). At median follow-up of 26.3 months, median overall survival was 19.4 months and 3-year overall survival was 38.6% (95% confidence interval 24.5% to 60.8%).

CONCLUSIONS

Neoadjuvant CRT with DCP is active (pCR + near-pCR = 53.7%) but toxicity is significant. Further evaluation of this regimen in an unselected population is not recommended.

CLINICALTRIALSGOV IDENTIFIER

NCT00757172.

Phase II multicenter study of erlotinib with radiation therapy (RT) for elderly patients (pts) with esophageal carcinoma (EC): Final report

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Background: Elderly pts with comorbidities have limited Rx options for localized EC. High EGFR expression correlates with poor response to RT. We examined the safety and efficacy of erlotinib, an oral EGFR tyrosine kinase inhibitor with RT in these pts.

Methods: Pts older than 65 yrs ineligible for platinum based Rx with carcinoma of the thoracic esophagus or gastroesophageal junction received erlotinib 150mg PO QD for one year starting D1 of RT [50.4 Gy D1-28 (M-F) at 1.8 Gy per fraction]. Assessments- mucosal response by EGD 4-8 wks post RT; RECIST response by CT q3mo. Endpoints: Primary- overall survival (OS), secondary- quality of life (QOL) using the FACT-E QOL tool, progression free survival (PFS) and toxicity; correlative- pre-treatment tumor EGFR and pEGFR expression by immunohistochemistry (IHC).

Results: The study was closed after 17 of planned 35 pts were included due to poor accrual. Baseline characteristics: median age 78 yrs (66-91); gender M/F: 11/6; ECOG PS 0/1/2=2/12/3; stage I-1, II=5, III=7 and IVa= 4; histology: adenocarcinoma 16, squamous cell 1; dysphagia at baseline 13/17 (76%). Median OS was 7.3 months (95% CI: 4.5-22.3) with 12 pts dead (5 alive, 3 still on treatment). Reason for coming off study (n=14): disease progression (n=6), toxicity (n=5), withdrew consent, completed one year of treatment, death from unrelated cause (n=1 each). There were 2 mucosal CRs and one residual carcinoma in situ, 3 partial endoscopic responses of the 9 pts who had post RT endoscopy. Estimated PFS is 5.3 months (95% CI: 2.4-11). Sites of progression- distant 3, locoregional 6, unknown 5 and too early 3. Estimated one year survival is 26 %, 3 pts lived >12 months. Smoking status- current/past/never 3/12/2. Treatment related toxicities (any grade n=or>5) were, rash (16), fatigue (16), diarrhea (11), lymphopenia (10), anorexia (7) and dehydration (6) and 21 grade 3/4 toxicities occurred. IHC results- EGFR, neg: 1/16; pos: 15/16 and pEGFR, neg: 2/16; pos:14/16.

Conclusions: For elderly pts with localized EC and no chemotherapy options, erlotinib monotherapy with RT is a tolerable therapy with modest activity. Further studies are needed to define the role of EGFR inhibition with RT in EC.

No significant financial relationships to disclose.

Microscopic and macroscopic tumor and parenchymal effects of liver stereotactic body radiotherapy

PURPOSE

To describe the histologic and volumetric changes in normal liver tissue after stereotactic body radiotherapy (SBRT) for liver metastases.

METHODS AND MATERIALS

Pre- and post-SBRT imaging studies were analyzed to evaluate the effect of SBRT on normal liver volume (NLV) in 15 patients treated in a prospective clinical trial. Two other patients underwent exploratory surgery after SBRT and histologic analyses of the irradiated liver were performed to characterize the pathologic effects of SBRT.

RESULTS

In the 15 patients studied quantitatively, the total NLV had decreased transiently at 2-3 months after SBRT and then began to regenerate at 3-8 months after SBRT. The median NLV reduction at the maximal observed effect was 315 cm(3) (range, 125-600) or 19% (range, 13-33%). Among the several dosimetric parameters evaluated, the strongest linear correlation was noted for the NLV percentage receiving 30 Gy as a predictor of maximal NLV reduction (r(2) = 0.72). The histologic changes observed 2 and 8 months after SBRT demonstrated distinct zones of tissue injury consistent with localized veno-occlusive disease.

CONCLUSION

The well-demarcated focal parenchymal changes after liver SBRT (demonstrated both radiographically and histologically) within the high-dose zone are consistent with a threshold dose-induced set of phenomena. In contrast, the more global effect of NLV reduction, which is roughly proportional to whole organ dose parameters, resembles more closely an effect determined from radiobiologically parallel architecture. These observations suggest that modeling of normal tissue effects after liver SBRT might require different governing equations for different classes of effects.

How should we describe the radioblologic effect of extracranial stereotactic radlosurgery: equivalent uniform dose or tumor control probability?

Extracranial stereotactic radiosurgery (ESR) is now undergoing clinical investigation at numerous institutions as a treatment for solitary malignant lesions. Because there is no standard ESR technique, the same minimum dose might be applied through widely variable target dose-volume histograms. For multicenter trials of ESR or interinstitutional comparisons, a reliable index of radiobiological dose equivalency might facilitate the evaluation of dose-response relationships. Equivalent uniform dose (EUD) and tumor control probability (TCP) were considered for this application. While EUD appears more robust for the prospective description of ESR, TCP is expected to remain more valuable for a post hoc estimation of radiosensitivity parameters.