HEAD & NECK CANCER PART-4
(All the articles published in past are available at www.shyamhemoncclinic.com/blog/)
Question: Dr. Chiragbhai, thank you for explaining in detail about neck node levels; role of CT, MRI and new imaging modality PET-CT scan in staging work up. Also for stressing the importance of good clinical examination to compliment advance tests.
Ans: Yes. It is important to note that good clinical examination is still very important. That is why even the official staging system takes into account both examination and radiology tests to assign stage. This method is known as TNM staging which is used worldwide for all sites of head and neck region, and most other body sites. Few body sites have alternate staging systems as well, such as for nasopharynx. These cancers are divided in broad categories for purpose of treatment planning:
1. Oral cavity and Lip 6. Thyroid
2. Oropharynx 7. Salivary glands
3. Hypopharynx 8. Paranasal sinuses
4. Larynx 9. Unknown primary
All sites have few differences in staging, details of which are out of scope for this article. However general concepts for our readers are following:
1. Early stage refers to stage 1, 2, and low volume stage 3 (such as T1 or T2 with N1)
2. Locally advance stage is stage 3, 4 (4 a and b). 4 b is unresectable.
3. Metastatic disease is stage 4c with distant spread of disease.
4. Any patient with clinically palpable lymph node is at least stage 3. Node size more than 6 cm i.e. N3 node is inoperable disease.
5. Criteria for unresectability vary, but most commonly agreed criteria are: base of skull involvement, fixation to prevertebral fascia, carotid encasement, ptergoid muscle involvement. Many would also consider very poor functional outcome, need for total glossectomy, or low chance of obtaining negative margins also as unresectable.
With newer surgical and reconstruction techniques, unresectability criteria however are evolving.
Que: Why is it important to have so many divisions? As I understand, all patients should be operated if possible, and radiated if inoperable, isn’t it?
Ans: Fortunately the field has evolved a lot more. Each subsite needs to be evaluated differently. Decision making takes into account not just best option for cure but also functional and cosmetic outcome. Head and neck region requires the largest multidisciplinary team, preferably involving specialized head and neck cancer surgeon (not a general cancer surgeon), radiation oncologist, medical oncologist, dentist, speech therapist, nutritionist. In specific cases, other important members may be audiologist, physical and occupational therapist, prosthodontists, and even a psychiatrist.
Very broadly speaking, surgery is the mainstay of therapy for lip and oral cavity, thyroid, salivary gland. For other sites, surgery frequently results in poor functional outcome, affecting speech/ swallowing, and/or respiration in a significant manner. Hence, radiation and chemotherapy combination has replaced surgery in many cases OR radiation surgery and chemotherapy are used in varying combinations and sequences. In advance cases, all three modalities are frequently required. Thus decision making is complex and involves not only stage but also functional outcome, and patient choice. For example, cancer of larynx if treated by surgery i.e. total laryngectomy, results in complete loss of voice. However the landmark study that compared surgery with radiation+chemotherapy showed that later provided equivalent results and voice preservation at the same time. Hence it is standard of care for about two decades now to treat cancer of larynx without surgery in most cases. Same is true for hypopharynx, base of tongue etc.
So now radiation and chemotherapy combination is an option for even operable patients, in many cases. Chemotherapy or newer medicines are not curative by itself.
April 10th 2015.
Dr. Chirag A. Shah; M.D. Oncology/Hematology (USA), 079 26754001. Diplomate American Board of Oncology and Hematology. Ahmedabad. email@example.com
Shyam Hem-Onc Clinic. 402 Galaxy, Near Shivranjani, Opp Jhansi ki Rani BRTS, Ahmedabad. www.shyamhemoncclinic.com