Management of early esophageal cancer

The degree of segmental aneuploidy measured by total copy number abnormalities predicts survival and recurrence in superficial gastroesophageal adenocarcinoma

Background

Prognostic biomarkers are needed for superficial gastroesophageal adenocarcinoma (EAC) to predict clinical outcomes and select therapy. Although recurrent mutations have been characterized in EAC, little is known about their clinical and prognostic significance. Aneuploidy is predictive of clinical outcome in many malignancies but has not been evaluated in superficial EAC.

Methods

We quantified copy number changes in 41 superficial EAC using Affymetrix SNP 6.0 arrays. We identified recurrent chromosomal gains and losses and calculated the total copy number abnormality (CNA) count for each tumor as a measure of aneuploidy. We correlated CNA count with overall survival and time to first recurrence in univariate and multivariate analyses.

Results

Recurrent segmental gains and losses involved multiple genes, including: HER2, EGFR, MET, CDK6, KRAS (recurrent gains); and FHIT, WWOX, CDKN2A/B, SMAD4, RUNX1 (recurrent losses). There was a 40-fold variation in CNA count across all cases. Tumors with the lowest and highest quartile CNA count had significantly better overall survival (p = 0.032) and time to first recurrence (p = 0.010) compared to those with intermediate CNA counts. These associations persisted when controlling for other prognostic variables.

Significance

SNP arrays facilitate the assessment of recurrent chromosomal gain and loss and allow high resolution, quantitative assessment of segmental aneuploidy (total CNA count). The non-monotonic association of segmental aneuploidy with survival has been described in other tumors. The degree of aneuploidy is a promising prognostic biomarker in a potentially curable form of EAC.

[Early esophageal cancer: pro surgical resection]

Endoscopic methods are increasingly propagated as oncologically adequate and less invasive treatment modalities for early esophageal cancer compared to surgery. The superiority or equality of endoscopic treatment has, however, so far not been proven by controlled trials. Current guidelines and an analysis of recently published data support surgical resection and lymphadenectomy as the standard of care for early esophageal cancer. This is based on the following arguments: 1) a reliable complete tumor resection with clear margins in all directions (R0 resection) including removal of all precancerous and precursor lesions can currently only be achieved by surgical resection, 2) none of the currently available staging tools allows definitive exclusion of lymphatic spread. A potentially curative surgical lymphadenectomy should thus only be omitted in well-defined subgroups. 3) In experienced hands surgical resection and lymphadenectomy can be performed with low mortality and morbidity, 4) reproducible and reliable data on long-term recurrence-free survival and quality of life are currently only available for surgical series. Thus, endoscopic therapy for early esophageal cancer is an alternative to surgical resection with lymphadenectomy only in patients unfit for surgery and in strictly defined low-risk situations.

SEOM clinical guidelines for the treatment of oesophageal cancer

Oesophageal cancer is currently the eighth most common malignancy worldwide. The incidence varies enormously between geographic areas, with increased incidences (>100/100,000) in Asia, and central and south Africa. The incidence of oesophageal cancer in Spain has been approximately 8/100,000 among men and 1/100,000 among women. Oesophageal cancers are histologically classifi ed as squamous cell carcinoma (SCC) or adenocarcinoma, both with different associated risk factors. While SCCs have become increasingly less common, the incidence of adenocarcinoma has risen steeply. In the SEOM Clinical Guidelines for Oesophageal Cancer we propose rules for adequate initial diagnosis and staging as well as treatment recommendations from early to advanced disease.