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Conference Coverage

American Society of Clinical Oncology Gastrointestinal Cancer Symposium

The American Society of Clinical Oncology (ASCO) hosted its annual Gastrointestinal (GI) Cancers Symposium in San Francisco, California, from January 18-20, 2018. The GI Cancers Symposium is a specialized oncology event designed to provide scientific and educational content for members of the GI cancer care and research community. The 3-day meeting encompasses the latest science in cancers of the esophagus and stomach; the pancreas, small bowel, and hepatobiliary tract; and the colon, rectum, and anus.

The target audience of this symposium is physicians and researchers interested in the prevention, screening, evaluation, and management of GI cancers, including, but not limited to medical, surgical, and radiation oncologists; pathologists; radiologists; and other translational-oriented laboratory scientists, according to the program.

The 2018 meeting concentrated on the theme of “Multidisciplinary Care: Local Practice, Global Outcomes,” highlighting cutting-edge strategies and innovations in GI cancer care and research with valuable perspectives from the international experts on the faculty and planning committees. 

Although incidence and mortality rates continue to increase, emerging science offers new options for multidisciplinary precision care through new and emerging diagnostic approaches, as well as innovative therapy options. Continued evolution in the clinical evidence base highlights the ongoing need for education in this area to ensure that all members of the cancer care team stay current on emerging therapies and diagnostic technologies.


Lenvatinib vs Sorafenib in First-Line Unresectable Hepatocellular Carcinoma

A recent phase 3 study found lenvatinib mesylate superior to sorafenib as a first-line therapy in hepatocellular carcinoma. Results of the study were presented during the ASCO conference.

Hepatocellular carcinoma is credited with 85% to 90% of primary liver cancer worldwide. While early-stage disease is treatable by a variety of means, treatment options for unresectable disease are limited and the prognosis is poor.

Eisai’s REFLECT study is a multicenter, randomized, open-label, global study comparing the efficacy and safety of lenvatinib vs sorafenib as a first-line treatment for patients with unresectable hepatocellular carcinoma. The study randomized 954 patients (1:1) to lenvatinib (12 or 8 mg once daily, depending on baseline body weight; n = 478) or sorafenib (400 mg twice daily; n = 476).

Researchers assessed for overall survival, with the goal of demonstrating noninferiority. Other factors included progression-free survival (PFS), time to progressions (TTP), objective response rate (ORR), and quality of life. Treatment was continued until disease progression or unacceptable toxicity.

The independent imaging review based on both RECIST 1.1 and modified RECIST confirmed the investigator’s findings of increases in PFS, TTP, and ORR for patients receiving lenvatinib compared with sorafenib. Lenvatinib also offered superior reduction in tumor size.

Common adverse events associated with lenvatinib in the study included hypertension, diarrhea, decreased appetite, weight loss, and fatigue. All of these events are consistent with the known safety profile of lenvatinib.

Eisai submitted applications to the Food and Drug Administration in July 2017 for an additional indication for lenvatinib for the treatment of hepatocellular carcinoma.—Zachary Bessette

 

Liquid Biopsy Test May Improve Detection of Early-Stage Colorectal Cancer

A liquid biopsy can detect colorectal cancer at an early stage and with accuracy near 90%, according to research presented at the conference.

“Our study is important because there is still some reticence among patients to use stool-based tests or have an invasive exam like colonoscopy to detect colorectal cancer,” said Wen-Sy Tsai, MD, PhD, assistant professor, Linkou Chang Gung Memorial Hospital (Taipei, Taiwan), in an ASCO press release (January 16, 2018). “Our results may point to a solution for people who are reluctant to get an initial screening colonoscopy or are not compliant in returning stool-based test kits that they get from their doctors.”

Dr Tsai and colleagues conducted a study enrolling 620 patients older than 20 years who were frequent hospital visitors for routine colonoscopies or a confirmed colorectal cancer diagnosis. Prior colonoscopy or biopsy results showed 438 of the patients had either adenomatous polyps or early- to late-stage colorectal cancers. Remaining participants—designated as the control group—showed no signs of a pre-cancerous growth or colorectal cancer.

All of the patients had their blood tested for circulating tumor cell analysis through a routine blood draw. The resulting samples were processed using CMx, an assay that captures rare circulating tumor cells on a liquid-coated chip that mimics human tissue. Results of these assays were further compared in a blinded analysis with the colonoscopy results.

Results showed that sensitivity ranged from 77% for detection of circulating tumor cells in polyps to 87% for stage I-IV cancers. After calculating the accuracy of the results by taking into account sensitivity and specificity, researchers found that the accuracy of the test ranged from 84% to 88% between polyps and cancerous samples.

Additionally, they noted that the accuracy of this test was superior to that of fecal occult blood testing.

“Recent surveys have found that over 80% of patients who are reluctant to undergo colonoscopy screening would be receptive to a blood test over stool-based tests,” said coauthor Ashish Nimgaonkar, MD, gastroenterologist and medical director, Center for Bioengineering Innovation and Design, Johns Hopkins University, in the press release. “A number of studies have found that affordability was the number one reason for not being screened; however, this test is highly affordable and can potentially cost less than $100.”

Their test, researchers added, could be used with other solid tumors, such as breast, lung, and prostate cancer.—Zachary Bessette

 

Colorectal Cancer Tumor Location Correlates With Outcomes

Another study presented at ASCO identified the difference between right-sided and left-sided tumors in regard to disease-free survival (DFS) outcomes in patients with late stage, high-risk colorectal cancer.

Registry studies and meta-analyses have shown that patients with right-sided colorectal cancer who develop metastatic disease have a worse prognosis than patients with left-sided tumors. Patients with left-sided tumors may also benefit from treatment with epidermal growth factor receptor inhibitors. However, most data confirming these trends exist only in patients who have relapsed.

One such study (SCOT) randomly assigned 6088 patients between 2008 and 2013 from 244 multinational cancer centers. Results showed that 3-month adjuvant chemotherapy containing oxaliplatin was noninferior to 6-month adjuvant therapy among patients with stage III and high-risk stage II colorectal cancer.

Mark P Saunders, MD, PhD, MBBS, MRCP, FRCR, consultant clinical oncologist, The Christie NHS Foundation Trust (United Kingdom), and colleagues aimed to determine whether tumor sidedness had an impact on DFS in the SCOT study. Among the 3219 patients in the evaluable study population, 1207 had right-sided tumors (41% tumor size 4; 17% stage II) and 2012 had left-sided tumors (24% tumor size 4; 21% stage II).

They found that 80% of patients with left-sided tumors achieved 3-year DFS, compared with only 73% of patients with right-sided tumors (hazard ratio [HR], 1.4; 95% CI, 1.21-1.61). After adjusting for T-stage and N-stage, the HR was reduced to 1.21 (95% CI, 1.05-1.40).

Researchers acknowledged that the data was not significant for tumor sidedness affecting the impact of 3 months vs 6 months of chemotherapy on 3-year DFS (right-sided, HR, 1.04; 95% CI, 0.84-1.29; left-sided, HR, 0.91; 95% CI, 0.75-1.09).

While Dr Saunders and colleagues admitted that cohort size limited any further subset analysis, the data clearly suggests that right-sided tumors are associated with worse DFS in late stage, high-risk colorectal cancer.

“This is the first study to show that unselected patients with right-sided tumors had a worse DFS compared [with] left-sided tumors,” wrote Dr Saunders. “This implies that prognosis is influenced primarily by greater recurrence rather than the contributing factors that influence overall survival.”—Zachary Bessette

 

Cost-Effectiveness of Radiation Techniques for Locally Advanced Rectal Adenocarcinoma

A comparative effectiveness study presented at the ASCO conference examined the costs associated with short-course radiation therapy vs long-course chemoradiation for locally advanced rectal adenocarcinoma.

Currently, the standard of care in the United States for locally advanced rectal cancer is long-course chemoradiation (50.4 Gy in 28 fractions with concurrent chemotherapy) followed by surgery and adjuvant chemotherapy. However, many other countries use short-course radiation therapy (25 Gy in 5 fractions) for this disease.

Ann C Raldow, MD, MPH, radiation oncologist, UCLA David Geffen School of Medicine (Los Angeles, CA), and colleagues conducted a study to analyze the cost-effectiveness of these 2 radiation techniques. Researchers developed a cost-effectiveness model that simulated 10-year outcomes for patients aged 65 years who were treated with either short-course radiation therapy or long-course chemoradiation.

Probabilities, utilities, and costs based on the literature and Medicare Fee schedules were used to determine the incremental cost-effectiveness ratio (ICER) of both treatments. The predefined threshold for cost-effectiveness was $100,000 per quality-adjusted life-year (QALY) or less.

Results of the study showed that short-course radiation therapy had an ICER of $351,731 per QALY, which made it more cost-effective than long-course chemoradiation. Short-course radiation therapy remained the more cost-effective strategy with 3D-conformal treatment for long-course chemoradiation, but intensity modulated radiation therapy for short-course radiation therapy (ICER, $314,022 per QALY).

Furthermore, one-way sensitivity analysis showed that long-course chemoradiation became the more cost-effective approach when the utility of no evidence of disease with abdominoperineal resection state was below 0.61. Two-way sensitivity analysis showed that the more cost-effective strategy for a given patient depended on the utilities for the no evidence of disease with low anterior resection and abdominoperineal resection states.

Dr Raldow and colleagues concluded that while short-course radiation therapy is a more cost-effective strategy than long-course chemoradiation for locally advanced rectal adenocarcinoma, the importance of patient preference-sensitive care cannot be understated.—Zachary Bessette

 

Decreased Hospitalizations, Shorter Length of Stay Does Not Reduce Cancer-Related Costs

One study presented at the 2018 GI Cancers Symposium identified trends in incidence and costs of GI cancer-related hospital admissions in the United States.

As recent as 2009, adult patients had 4.7 million cancer-related hospitalizations in the United States. Hospital stays as a result of a cancer diagnosis accounted for $20.1 billion in costs and 6% of adult inpatient hospital costs in that year. A better understanding of GI cancer-specific health care utilization is needed.

Aileen Deng, MD, and Atrayee Basu Mallick, MD, of the Thomas Jefferson University Hospital (Philadelphia, PA), evaluated GI cancer incidence and costs resulting from hospital admission from 1997 to 2014. Researchers reviewed the National Inpatient Sample Database to identify all patients with principle discharge diagnoses of esophageal, stomach, colon, rectum and anus, liver and intrahepatic bile duct, and pancreas cancer.

Temporal trends in the number of hospital admissions, length of stay, hospitalization cost, and mortality rates were gathered through Health Care Utilization Project Network (HCUPnet).

Results of the evaluation showed that GI cancer-related hospital admissions decreased from 1997 to 2014 (230,537 vs 221,220, respectively). While the number of hospital admissions decreased for esophageal (12,157 vs 11,885), stomach (23,528 vs 21,800), colon (110,939 vs 90,135), rectum and anus (43,807 vs 40,160), incidence has increased for liver and intrahepatic bile duct (11,243 vs 21,775) and pancreas cancer (28,862 vs 35,465).

Additionally, researchers reported that while the mean length of stay decreased from 9.6 days in 1997 to 7.6 days in 2014, the mean hospital charges per patient—after adjusting for inflation—increased 127% ($34,747 vs $78,742, respectively). Among the highest increase in mean hospital charges per patient were liver and intrahepatic bile duct ($27,128 vs $74,619), rectum and anus ($32,566 vs $90,789), and pancreas cancer diagnoses ($33,562 vs $75,981).

Drs Deng and Mallick concluded that, despite the decrease in GI cancer-related hospital admissions and mean length of hospital stay from 1998 through 2014, costs of hospitalizations have increased significantly, particularly in liver and intrahepatic bile duct, rectum and anus, and pancreas cancer. This conclusion led them to the finding that shorter length of stay alone has not reduced costs of hospitalizations in GI cancers. “There remains a growing need to understand health care costs and to develop effective value-based interventions in gastrointestinal cancer-related hospital admissions,” they wrote.—Zachary Bessette

 

Gastric Cancer Treatment Costs in the US Vary by Region

Regional variation exists in the treatment costs for patients with curative gastric cancer despite guidelines promoting appropriate care and health care delivery, according to a presentation at the 2018 GI Cancers Symposium.

Gastric cancer remains difficult to treat, and little is known about the economic burden of the disease. Multiple guidelines describe the curative treatment landscape for gastric cancer in a universal health care system, in which equal access and uniform health care delivery is expected. However, a common belief is that regional variation in practice exists and likely results in increased health care costs.

A group of Canadian researchers led by Yunni Jeong, MD, University of Toronto (Ontario, Canada), investigated the costs of treating curative gastric cancer and explored regional variation in costs as well as identified factors that drive these costs. Researchers conducted a patient-level cost analysis of curative-intent stage I-III gastric cancer diagnosed from 2005 through 2008 from the perspective of a universal health care system, using a 26-month time horizon. A total of 722 patients were enrolled in the study.

Clinical and stage data were abstracted from a provincial chart review. Administrative health care databases provided costs associated with physician billings, same day surgery, hospitalization, drug benefits, emergency department visits, continuing care, and long-term care. These incurred costs—which were inflated to 2017 United States dollars—were compared among health care regions.

Results of the study showed that mean costs per region ranged from $55,650 to $92,852 across 14 health care regions. The lowest contributing cost sector was long-term care, while the highest contributing cost sector was from hospital admissions.

A linear regression model identified a laparoscopic surgical approach as predictive of lower costs, while age 70 or older and death at 1 year from diagnosis was predictive of higher costs.

Dr Jeong and colleagues concluded that regional variation exists in the treatment costs for patients with curative gastric cancer despite guidelines directing appropriate care and health care delivery in a universal health care system. They further cautioned that government intervention is needed to ensure quality care delivery across regions for curative gastric cancer.—Zachary Bessette