Esophageal Cancer In 2013
Esophageal cancer 20 years ago was mostly secondary to smoking and alcohol use. The pathology was mostly squamous cell in etiology and was typical of an older population. Over the last decade squamous cell etiology worldwide has markedly decreased and adenocarcinoma has dramatically increased. The etiology is from Barrett's esophagus and the patient population is mostly overweight younger males with changes in the columnar epithelium of the esophagus from chronic gastro esophageal reflux.
The esophagus has no lining and is very elastic, therefore most of the time when esophageal cancer is diagnosed it is locally advanced requiring chemotherapy, radiation therapy and surgery.
In general, large tumors are treated with chemotherapy or chemo radiation, in order to render the tumor resectable. Systemic therapy improves distant recurrence rates while radiation helps by decreasing local recurrence.
The chemotherapeutic agents mainly used in squamous cell carcinoma were 5FU and cisplatin. This histology was also very radioresponsive. Adenocarcinomas have been treated mainly with the taxanes and carboplatin in the neoadjuvant setting.
Ongoing trials for adenocarcinoma that over express HER2 NEU have added to chemo or chemo radiation the monoclonal antibody Herceptin, which appears to be very promising. Only 30% of adenocarcinomas of the esophagus over express the HER2 NEU receptor.
The most important risk factor for esophageal adenocarcinoma is Barrett's esophagus. Once there is a diagnosis of Barrett's esophagus, patients are started on surveillance protocol to follow the progression from low-grade dysplasia to high-grade dysplasia, which then can progress to carcinoma in situ and then invasive adenocarcinoma.
Currently for high-grade lesions and carcinoma in situ intramucosal endoscopic resection and ablative modalities are standard of care. Photodynamic therapy is a modality, which uses a drug as a photo sensitizer combined with laser light causing necrosis of tumor cells, a process, which is minimally invasive.
Radiofrequency ablation has been used since 2004 and is therefore the preferred modality just because of longer follow up and amount of research available. The balloon is introduced and delivers energy with destruction of a limited area of mucosa but not submucosal.
Cryoablation therapy is the newest modality uses liquid nitrogen low pressure spray the freeze/thaw cycle disrupts the cell membranes causing cell death.
All these modalities are very safe and effective for high-grade dysplasia and minimally invasive disease replacing esophagectomy. Hopefully in the near future targeted agents will replace chemotherapy in the treatment of esophageal cancer with better results and less toxicity.