Head and Neck cancer -12 – CUP Salivary gland

HEAD & NECK CANCER PART-12

(All the articles published in past are available at www.shyamhemoncclinic.com/blog/)

Question: Thank you Chiragbhai for a very enlightening article on palliative care, end of life care. It is such a new concept for most readers. It was amazing to read that there is actually MD degree in palliative medicine in the western world, that this care is very science driven, and not just tender loving care. Many concepts of palliative care can be learned easily by General Practioners. They can provide good care to many such patients at their homes or in opd, day care. Interested readers should visit www.shyamoncologyfoundation.com, and review Karunalay or visit website of Pallium India. Basic pain management, wound dressing, nutrition, and care of few other symptoms can be easily learned by general practioners. Dr Bhavish at Karunalay will be happy to guide. GCRI is even starting a formal training program for those who wish to get more detailed training and a formal degree.

Also it was very nice to know that there are at least two centers in Ahmedabad city providing completely free care, at KARUNALAY and at GCRI.

Now can we discuss few specific sites in head and neck cancer, which may need a special mention?

Ans: Definitely. But first we should start with an interesting category “cancer of unknown primary site”. This is an unusual condition, in about 10% of patients, we cannot find a primary tumor. But there are enlarged neck nodes, which show cancer on biopsy. Most common is squamous cell carcinoma.

On detailed examination, CT scan, MRI etc one cannot find origin of this cancer, in entire body. Ideally, examination of entire head and neck region should be done under anesthesia, with directed biopsies of base of tongue, nasopharynx, hypopharynx, and same side tonsillectomy. Tonsillectomy is not standard of care. With lower neck nodes, one should keep in mind lung, gastrointestinal tract, and sometimes other areas.

In some cases, it is adenocarcinoma. Origin of these could be from thyroid, salivary gland, lung, gastrointestinal tract etc. If there is any doubt about pathology, especially if it is not classical squamous cell carcinoma, it is important to obtain core needle biopsy or excisional node biopsy. This is important not to miss lymphoma or other uncommon diagnoses in this region, malignant or benign.

PET CT scan has shown better results compared to past in finding a primary, but still it is not 100%. It should however preferably be a part of evaluation in most such cases.

There are standard principles of treatment in such cases, depending on site of the enlarged lymph nodes. Clinicians judge possible site based on lymph node area involved, as there is a fairly established lymphatic drainage for most sites. For example, a level 1 node is more likely related to primary in tongue or floor of mouth, but level 2 more likely base of tongue or tonsil. Two options exist for treatment. One is neck dissection followed by radiotherapy (or chemoradiotherapy if extracapsular extension of disease) to cover potential primary sites. Second option is chemoradiotherapy without neck dissection. Second option is increasingly being utilized with now better radiotherapy precision as well as more early stage diagnoses. Also, non tobacco related cancers (mainly due to HPV) are also better treated with chemoradiation. For nodes larger than 3 cm, neck dissection is still preferred before chemoradiation.

Que: Very interesting. Even after so many scans and other tests, we cannot find a primary tumor in some cases. Nature is always one step ahead of us.

Ans: Yes. But that is what keeps medicine a very interesting field. Next specific site is salivary gland tumors. These are much less common, but important to know since they are treated very differently. There is no known risk factor, such as Tobacco or Alcohol.

It has many different histologies, but the most common are mucoepidermoid carcinoma, adenoid cystic carcinoma, and adenocarcinoma. Surgery is the main form of treatment, even for recurrent tumors. Adjuvant radiotherapy is prescribed if there are adverse features. Chemotherapy has no established role in early stage, with or without radiotherapy. For recurrent tumors, when surgery is not feasible, chemotherapy can be given. However single agent or combination have low response rates and not very durable. Agents used are essentially same as in squamous cell head and neck cancers. There is growing interest in use of targeted therapies, as in most other cancer types. However there is no large trial, as these are uncommon cancers, and have so many different histologies. One may test tumor for targets with known targeted therapies, such as EGFR, Her 2, c-kit, ER PR and others. If positive, one may try respectively Gefitinib, Lapatinib, Imatinib, Hormone therapies etc. Response rates again are not established, and may not have any response rates. These limitations should be kept in mind while offering such therapies.

December 15th 2015.

Dr. Chirag A. Shah; M.D. Oncology/Hematology (USA), 079 26754001. Diplomate American Board of Oncology and Hematology. Ahmedabad. drchiragashah@gmail.com  Shyam Hem-Onc Clinic. 402 Galaxy, Near Shivranjani, Opp Jhansi ki Rani BRTS, Ahmedabad. www.shyamhemoncclinic.com