Is follow-up CT imaging of the chest and abdomen necessary after preoperative neoadjuvant therapy in rectal cancer patients without evidence of metastatic disease at diagnosis?

AIM

Patients with rectal cancer often undergo multiple CT scans prior to surgical resection. We propose that in patients with locally advanced rectal cancer without evidence of metastatic disease at presentation, CT imaging of the chest and abdomen after preoperative neoadjuvant therapy does not change clinical information or surgical management.

METHOD

An institutional review board-approved medical record review identified patients with contrast enhanced CT of the chest, abdomen and pelvis alone or in conjunction with (18)F-fluoro-2-deoxy-d-glucose/positron emission tomography imaging for staging of rectal cancer prior to and after neoadjuvant therapy. Eighty-eight patients were included in the study. Scans were reviewed for the presence of metastatic disease on initial and follow-up imaging prior to surgical resection.

RESULTS

Seventy-six (86%) of 88 patients had no evidence of metastasis at presentation. None of these patients developed metastatic disease after neoadjuvant therapy. Twelve (14%) had metastases at presentation. No study patient developed metastatic disease in a new organ.

CONCLUSION

Imaging after preoperative neoadjuvant therapy in rectal cancer does not change the designation of metastatic disease. Patients with locally advanced rectal adenocarcinoma without evidence of metastases may not benefit from repeat imaging of the chest and abdomen after neoadjuvant therapy.

Single-institution experience of preoperative chemoradiotherapy for locally advanced gastric cancer

99

Background: To examine acute toxicity and outcomes for patients treated with preoperative chemoradiotherapy (CRT) for gastric cancer.

Methods: Patients with gastroesophageal (GE) junction (Siewert type II and III) or stomach adenocarcinoma who underwent curative intent CRT followed by planned surgical resection at Duke University between 1987 and 2009 were reviewed. Tumors were staged according to AJCC 6th edition. Local recurrence was defined as radiographic or biopsy- proven disease within the radiation treatment field. Overall survival (OS), local control (LC) and disease-free survival (DFS) were estimated using the Kaplan-Meier method. Toxicity was graded according to CTCAE v4.0.

Results: Forty-eight patients (60% stage III, 8% stage IV) were included. Most (73%) had proximal (GE junction, cardia and fundus) tumors. Thirty-five percent had signet ring histology, 52% had poorly differentiated tumors and 10% had linitis plastica. Median age was 60 years and median RT dose was 45 Gy. All patients received concurrent chemotherapy (CT) with 40 (83%) receiving 5-FU-based CT. Rates of acute > grade 2 hematologic and non-hematologic toxicity were 38% and 10%, respectively. Six patients (13%) required treatment break and two (4%) were unable to complete the prescribed treatment course. Thirty-six patients (75%) underwent surgery. Patients did not undergo surgery due to distant metastases at laparotomy or restaging (n=9), patient refusal (n=2) or poor performance status (n=1). Pathologic complete response and R0 resection rates were 19% and 86%, respectively. Thirty-day surgical mortality was 6%. At 42 months median follow-up, 3-year actuarial OS for all patients was 40%. For those undergoing surgery, 3-year OS, LC and DFS were 50%, 73% and 41%, respectively.

Conclusions: Preoperative CRT for gastric cancer is reasonably well tolerated with acceptable rates of perioperative morbidity and mortality. In this patient cohort with advanced disease, LC, DFS and OS rates in resected patients are comparable to similarly staged, adjuvantly treated historic controls. Further study comparing neoadjuvant CRT to standard treatment approaches for gastric cancer is indicated.

No significant financial relationships to disclose.

Phase I study of dasatinib in combination with capecitabine, oxaliplatin, and bevacizumab followed by an expanded cohort in previously untreated metastatic colorectal cancer

513

Background: SRC is a non-receptor tyrosine kinase involved in normal and tumor cell signaling functions including cell proliferation, angiogenesis and survival. Dasatinib (D) is a potent inhibitor of SRC kinase activity. Preclinical data suggests the addition of D to standard chemotherapy agents for colon cancer may increase anti-tumor activity. We evaluated D in combination with capecitabine (C), oxaliplatin (O) and bevacizumab (B) in a phase I dose escalation study followed by an expanded cohort in 1st line colorectal.

Methods: For dose escalation, eligible patients had advanced solid tumors with adequate organ and bone marrow function and no increased risk for class-related toxicities. B and O were given intravenously, and C and D were orally administered; cycle length was 21 days. C was dosed at 850 mg/m2 on days 1-14; O was dosed at 130 mg/m2 and B was dosed at 7.5 mg/kg on day one of each cycle. D was dosed at 50 mg twice daily in cohort one and 70 mg once daily in cohort -1. Dose limiting toxicity (DLT) was assessed in cycle 1.

Results: Dose escalation is complete with 10 subjects evaluable for toxicity and 11 subjects evaluable for efficacy. Two DLTs were observed out of 5 evaluable subjects in cohort one. Six evaluable subjects were enrolled in the -1 cohort with 1 DLT. Possible grade ≥ 3 treatment-related adverse events (AEs) included neutropenia, febrile neutropenia, anorexia, diarrhea, fatigue, anemia, hypophosphatemia, hyponatremia and grade 5 GI-perforation. One non-treatment related death was due to disease progression. D-related nausea and fatigue were responsive to low dose oral steroids; fluid retention was responsive to diuretics. Of 10 subjects evaluable for efficacy, 1 subject had a partial response (PR), 2 had a minor response (MR), and 4 had stable disease (SD). Four subjects had disease control (PR, MR, or SD) ≥ 6 months.

Conclusions: D in combination with C, O and B is well-tolerated with a toxicity profile similar to standard C, O and B.The recommended phase II dose is C at 850 mg/m2 on days 1-14, O at 130 mg/m2 and B at 7.5 mg/kg on day one of each cycle, and D at 70 mg once daily. Enrollment in the expanded cohort of 1st line colorectal is ongoing.

[Table: see text]

A phase I study of erlotinib, bevacizumab, and external beam radiation therapy (RT) for patients with localized pancreatic carcinoma (PC)

281

Background: Localized PC is commonly managed with chemoradiotherapy, with or without surgical resection. The optimal combination of agents and doses is the subject of continued investigation. This phase I study examines the combination of two targeted radiosensitizing agents in combination with radiation therapy.

Methods: Eligible patients had resectable, borderline resectable or locally advanced adenocarcinoma. Patients received RT (1.8 Gy qd to 50.4 Gy) concurrent with bevacizumab and erlotinib. Dose-level 1 was bevacizumab 10 mg/kg weeks 1, 3 and 5 and erlotinib 100 mg daily, RT days only. Drug doses were escalated depending on encountered toxicity. The primary endpoint was determination of the maximally tolerated dose of this combination. Secondary endpoints included toxicity and activity assessment.

Results: Nine patients were enrolled in the phase I study. Maximal EUS/CT stage was T2N0 (n=1), T3N0 (n=1), T3N1 (n=2) or T4N0 (n=5). Of 3 patients in dose-level 1, two had radiographic stable disease (SD) and one partial response (PR). One pt underwent exploratory laparotomy and found to be unresectable, experiencing prolonged postoperative incisional healing. Three patients were then enrolled at dose-level 2 (bevacizumab 10 mg/kg, erlotinib 125 mg). Two had SD and one progressive disease (PD). One pt underwent exploratory laparotomy, aborted due to previously undetected hepatic metastases. Three patients were then enrolled at dose-level 3 (bevacizumab 10 mg/kg, erlotinib 150 mg). One pt had SD and two PR. One pt underwent distal pancreatectomy, experiencing postoperative pancreatic leak and abscess formation. All patients with elevated CA 19-9 at baseline had a decrease, with amedian decrease of 69% (R:13-93%). Dose-limiting toxicity (DLT) was not encountered at any dose-level. Primary non-dose limiting toxicities in all cohorts included NCI CTCAE v3.0 grade 1-2 nausea/vomiting, rash, diarrhea, fatigue, and anorexia.

Conclusions: Concurrent chemoradiotherapy utilizing erlotinib and bevacizumab is reasonably well-tolerated. The recommended phase II dose is bevacizumab 10 mg/kg weeks 1, 3, and 5 and erlotinib 150 mg RT days only. Phase II accrual is underway.

[Table: see text]

Carcinoma of the ampulla of Vater: Patterns of failure after resection and benefit of adjuvant radiotherapy

254

Background: Ampullary carcinoma is a rare malignancy. Despite radical resection, survival rates remain low with high rates of local failure. To define the role of radiation therapy and chemotherapy with surgery, we performed a single institution analysis of treatment- related outcomes.

Methods: A retrospective analysis was performed of all patients undergoing potentially curative therapy for adenocarcinoma of the ampulla of Vater at Duke University Hospitals between 1975 and 2009. Local control (LC), overall survival (OS), disease-free survival (DFS), and metastases-free survival (MFS) were estimated using the Kaplan-Meier Method.

Results: One hundred thirty-seven patients with ampullary carcinoma underwent potentially curative pancreaticoduodenectomy. Sixty-one patients undergoing resection received adjuvant (n= 43) or neoadjuvant (n=18) radiation therapy with concurrent chemotherapy (CRT). Patients receiving radiotherapy were more likely to have poorly differentiated tumors. Median radiation dose was 50 Gy. Median follow up was 8.8 years. Of patients receiving neoadjuvant therapy, 67% were downstaged on final pathology with 28% achieving pathologic complete response. Three-year local control was significantly improved in patients receiving CRT (88% vs. 55% p= 0.001) with trend toward a 3-year OS benefit in patients receiving CRT (62% vs. 46% p=0.074). Despite this, there was no significant difference in 3-year DFS (66% CRT vs 48% surgery alone p=0.09) or MFS (69% CRT vs 63% surgery alone p=0.337).

Conclusions: Long term survival rates are low. Local failure rates are high following radical resection alone and improved with CRT. Despite more adverse pathologic features in patients receiving CRT, survival outcomes were at least equivalent with a trend toward statistical significance. Given the patterns of relapse with surgery alone and local control benefit in patients receiving CRT, the use of chemoradiotherapy in selected patients should be considered.

No significant financial relationships to disclose.

A phase I study of gemcitabine plus dasatinib (GD) or gemcitabine plus dasatinib plus cetuximab (GDC) in refractory solid tumors

e15506

Background: Dasatinib (D) is a small molecule tyrosine kinase inhibitor with activity against both bcr-abl and src. Cetuximab (C) is a monoclonal antibody that blocks EGFR. Preclinical models suggest D reverses resistance to G. In addition, src and EGFR pathways interact; synergism of dual blockade by D + C is possible. We evaluated two combination regimens, GD and GDC, in a Phase I dose escalation study. Methods: Patients (pts) with advanced solid tumors were enrolled in cohorts of 3–6 to either GD or GDC. G was dosed in mg/m2 weekly for 3 of 4 weeks, D was dosed in mg PO BID, and C was dosed at 250 mg/m2 weekly after loading dose of C=400; cycle length was 28 days. Dose levels were as follows: 1) G 1000 + D 50 ± C; 2) G 1,000 + D 70 ± C; 3) G 1,000 + D 100 ± C. Standard cycle 1 DLT definitions were used. Eligible pts had advanced solid tumors, adequate organ and marrow function, and no co-morbidities that would increase risk of toxicity. Serum, plasma, and skin biopsy biomarkers were obtained pre- and on treatment. Results: 25 pts have been enrolled, including 21 with pancreatic adenocarcinoma, 3 of whom had received prior G. 21 pts were evaluable for toxicity and 18 for efficacy. Four DLT were observed: Gr 3 ANC with infection (GDC1, n=1), Gr 3 ALT (GD2, n=2), and Gr 5 pneumonitis (GDC2, n=1). Possible treatment-related adverse events in later cycles included: Gr3–4 ANC (n=4), Gr4 colitis (n=1), Gr3 bilirubin (n=2), Gr3 Hgb (n=2), Gr3 Plt (n=2), Gr3 edema/fluid retention syndrome (n=1), and Gr3 vomiting (n=2). One previously untreated pt had a partial response. Eight of 18 pts, 3 of whom had received prior G, had stable disease as best response, median duration = 5 months (range 1–7). Biomarker results are pending. Conclusions: The MTD of the GD arm is G1000/D50BID. Stable disease in previous G-refractory pts was noted. Hematologic toxicities were dose-limiting; later toxicities including hematologic, LFT changes, pneumonitis, and fluid retention were seen. To address these toxicities, once daily dosing of D will be explored, followed by an expanded cohort of G + daily D vs G + bid D in pts with treatment-naïve pancreatic cancer.

[Table: see text]

Bevacizumab (B) plus everolimus (E) in refractory metastatic colorectal cancer (mCRC)

4080

Background: For patients (pts) with mCRC, no standard therapy exists after progression on 5-FU, oxaliplatin, irinotecan, bevacizumab, and/or cetuximab/panitumumab. Preclinical data demonstrate combined VEGF and mTOR inhibition has greater anti-angiogenic and anti-tumor activity than either monotherapy. B inhibits VEGF; E inhibits mTOR. Phase I data in patients demonstrated B + E was safe and activity was seen in several pts with refractory mCRC. Methods: 25 pts with refractory mCRC were enrolled in an expanded cohort of B + E. Doses: B 10 mg/kg q2 wks; E 10 mg PO QD. Blood, skin, and tumor biopsies pre- and on-treatment were collected for markers of response and resistance. Results: At this time, 19 pts (10M: 9F) are evaluable for toxicity; 17 for efficacy. Median age 57 years (range 35–78). Median number prior regimens 3. All pts had prior B exposure; 17 pts had progressive disease on prior B-based therapy. There was one Grade (Gr) 4 adverse event (AE) of hypokalemia. Grade 3 AE related to treatment were bowel perforation/fistula, (n=2), hyperglycemia (3), hypokalemia (3), hypertension (2), fatigue (1), alk phos elevation (1; lab only), hypoalbuminemia (1), and volume depletion (1). Other events of interest were: Gr1–2 mucositis (n=10), Gr1 hyperlipidemia (11). Of 17 pts evaluable for response, 4 pts had SD as best response (median 24 wks, range 17–31+ wks); there were 3 minor responses in pts who had progressed on B (median 16 wks, range 16–27 wks). No CR or PR were seen. Biomarker data is pending. Conclusions: B+E has activity in refractory mCRC in pts who had progressed on a B-based regimen, suggesting B+E may overcome resistance to B. Patient accrual is continuing and updated data will be presented.

[Table: see text]

Bevacizumab (B) plus everolimus (E) and panitumumab (P) in refractory advanced solid tumors

3551

Background: In preclinical models, VEGF, mTOR, and EGFR inhibitors have anti-tumor and anti-angiogenesis effects as monotherapies and in combination. B inhibits VEGF; E inhibits mTOR; P inhibits EGFR. There is also potential for interaction between the pathways. Previously BE and BE + erlotinib were evaluated and showed signs of clinical activity. Methods: Patients (pts) with refractory advanced solid tumors were accrued in a phase I dose escalation of B + E + P on a 28d cycle. Dose levels are shown in the table below. DLT was defined as any treatment-related grade 4 heme, grade 3/4 non-heme adverse event (AE), or receiving <85% any study drug in Cycle 1. Blood, skin, and tumor biopsies pre- and on-treatment were collected for correlative biomarkers of angiogenesis. Results: At this time, 12 pts (3M: 9F) are evaluable for toxicity; 9 for efficacy. Median age: 54 years (range 23–72). 9 of 12 pts had prior B exposure. Dose level 1 was expanded due to 1/3 DLT, with total of 3/6 DLT (Grade (Gr) 3 mucositis (n=2), Gr3 hypokalemia (n=1)). Dose level -1 had 3/3 DLT (Gr3, Gr4 mucositis (n=2), Gr3 non-acneform rash (n=1)). Dose level -2 had 0/3 pts DLT. Gr 3–4 related toxicities in cycle 2+: hypokalemia (n=4); hypophosphatemia (n = 1); hypomagnesemia (n = 1); diarrhea (n=1); hoarseness (n=1). Other events of interest were: Gr1–2 mucositis (n=7); Gr1 hyperlipidemia (n=5); Gr1–2 hyperglycemia (n=4); Gr2 hypertension (n=2); Gr1–2 neutropenia (n=5); Gr1–2 thrombocytopenia (n=5). 8/9 evaluable pts had SD as best response (median 26 wks, range 8+ to 32+ wks): 1 pt with pancreatic cancer and progression on 2 prior EGFR inhibitors had prolonged 32+ wk SD. There was 1 minor response (23.3%) in a pt with bevacizumab-refractory ovarian cancer (32+ wks). No CR or PR were seen. Conclusions: B + E + P at full doses has dose limiting toxicities of rash and mucositis. B 10 mg/kg q2wks + E 5 mg q48h + P 4.8 mg/kg q2wks is the maximum tolerated dose. This dose is currently being expanded in 20 patients with extensive pre- and on-treatment biomarker analyses. Updated clinical and biomarker data will be presented.

[Table: see text]

[Table: see text]

Oxygen for relief of dyspnoea in mildly- or non-hypoxaemic patients with cancer: a systematic review and meta-analysis

The aim of this study was to determine the efficacy of palliative oxygen for relief of dyspnoea in cancer patients. MEDLINE and EMBASE were searched for randomised controlled trials, comparing oxygen and medical air in cancer patients not qualifying for home oxygen therapy. Abstracts were reviewed and studies were selected using Cochrane methodology. The included studies provided oxygen at rest or during a 6-min walk. The primary outcome was dyspnoea. Standardised mean differences (SMDs) were used to combine scores. Five studies were identified; one was excluded from meta-analysis due to data presentation. Individual patient data were obtained from the authors of the three of the four remaining studies (one each from England, Australia, and the United States). A total of 134 patients were included in the meta-analysis. Oxygen failed to improve dyspnoea in mildly- or non-hypoxaemic cancer patients (SMD=-0.09, 95% confidence interval -0.22 to 0.04; P=0.16). Results were stable to a sensitivity analysis, excluding studies requiring the use of imputed quantities. In this small meta-analysis, oxygen did not provide symptomatic benefit for cancer patients with refractory dyspnoea, who would not normally qualify for home oxygen therapy. Further study of the use of oxygen in this population is warranted given its widespread use.

A phase I study of bevacizumab (BV) plus ABT-510 in patients with advanced solid tumors

3541

Background: BV is a potent inhibitor of vascular endothelial growth factor (VEGF) with broad clinical activity both alone and in combination. ABT-510 is a 9 amino acid synthetic analog of the N-terminal region of thrombospondin (TSP-1), an endogenous inhibitor of angiogenesis. ABT-510 exhibits anti-angiogenic effects in preclinical models and has been well-tolerated as a single agent in previous Phase I & 2 studies. As a combination anti-angiogenesis therapy, we evaluated BV + ABT-510 in a phase I biomarker study. Methods: In cohorts of 3–6 patients, BV and ABT-510 were evaluated. BV was dosed in mg/kg IV q2weeks and ABT-510 was given daily in mg SC BID; cycle length was 28 days. Dose levels were as follows: (1) BV 5/ ABT-510 50; (2) BV 10/ ABT-510 50; (3) BV 10/ ABT-510 100. At the recommended phase II dose, 20 patients are being enrolled for detailed biomarker studies. DLT was defined as any hematological toxicity = grade 4 or grade = 3 non- hematological event in Cycle 1 related to treatment, with the exception of grade 3 hypertension adequately controlled by medication. Eligible patients had advanced solid tumors, adequate organ and marrow function, and no co-morbidities suggesting increased risk for class-related toxicities. Dermal wound angiogenesis assays were analyzed for visualization as well as phospho-VEGFR2, TGFβ, phospho-AKT, and thrombospondin-1 and -2, both pre- and on-treatment. Plasma was assayed for multiple angiogenic factors. Results: 22 patients have been enrolled; 17 are currently evaluable for toxicity and 14 for efficacy. No DLT were seen in any cohort. Possible treatment related adverse events occurring in later cycles included: gr3 GI bleed (n=1) and gr3 headache (n=1). 7 patients had stable disease as best response (range 8- 64+ weeks); 2 remain on therapy, one at 64+ weeks and one at 24+ weeks. Conclusions: BV + ABT-510 is well-tolerated and has hints of activity in refractory tumors. The recommended phase II dose is BV 10mg/kg IV q14d and ABT-510 100mg SC BID. Updated clinical and biomarker data will be presented.

No significant financial relationships to disclose.