ADENOID CYSTIC CARCINOMA & TREATMENT
Definition: What is "Adenoid cystic carcinoma"?
Adenoid cystic carcinoma (ACC) is an uncommon form of malignant neoplasm that develops within secretory glands, most commonly the major & minor salivary glands of the head & neck. Other sites of origin include the trachea, lacrimal gland, skin, breast & vulva. This neoplasm is defined by its characteristic histologic appearance. Adenoid cystic cancer (AdCC) is a very rare type of cancer that can develop in many different body sites. It most often arises in the areas of the head & neck, in particular the salivary glands; but has also been reported in the breast, lacrimal gland of the eye, lung, brain, bartholin gland & the trachea. It is sometimes known as adenocyst, adenocystic, malignant cylindroma, adenoidcystic, ACC, AdCC.
Symptoms & Signs
These depend largely on the place of origin of the tumor. Early lesions of the salivary glands present as painless masses of the face or mouth, usually growing slowly. Advanced tumors may present with pain or nerve paralysis, for this neoplasm has a tendency to invade peripheral nerves. Tumors of the lacrimal gland may develop as proptosis & changes in vision. ACC arising in the tracheobronchial tree may present with respiratory symptoms, while tumors arising in the larynx may result to changes in speech.
Treatment: How to Treat "Adenoid cystic carcinoma"?
Standard therapy includes surgical resection whenever possible, as it is the mainstay therapy. Based on clinical experience, many centers advocate postoperative radiotherapy to aid in limiting local failure. A few specialized centers provide neutron beam therapy which may be more effective than conventional radiation therapy. There appears to be no effective chemotherapy for metastatic and/or unresectable ACC, although some patients may get palliation. Investigational Therapy: Several clinical trials are thoroughly examining the effects of relatively new chemotherapeutic drugs (paclitaxel, gemcitabine, etc.) alone, or in combination with other drugs, in the control of metastatic or locally recurrent ACC.
A huge age range has been reported for adenoid cystic carcinoma, including cases in the pediatric age group. Most individuals are diagnosed with the disease in the fourth through sixth decades of their life. There is a slight female preponderance, with female outnumbering males approximately 3 to 2). No strong environmental or genetic risk factors have been identified. Damage to the DNA genome arises in the development of ACC, as it does in all cancers studied to date. Various studies have shown chromosomal abnormalities & genetic deletions arising in samples of ACC. There is some proof that the p53 tumor suppressor gene is inactivated in advanced & aggressive forms of this neoplasm. Otherwise the specific molecular abnormalities that underlie this disease process are not known.