Longest survivor of adenoid cystic carcinoma
The longest survivor of adenoid cystic carcinoma described was a 77-year-old woman, who survived for 33 years. In her case, the cancer was diagnosed in Bartholin’s gland and treated. However, during the 33 years, it came back four times [1].
Another long survival is a patient surviving 25 years with an adenoid cystic carcinoma of the lacrimal gland [2].
What is the success rate of treatment of adenoid cystic carcinoma?
Generally, the survival depends strongly on the stage, excision margin, and the perineural invasion of the tumor [3, 4].
The 5-year survival rate of adenoid cyst carcinoma is 70 to 91% [3, 5]. However, the 5-year survival rate depends strongly on treatment [6].
The best outcomes are achieved by combining surgery and radiotherapy, with 77 to 94% of all patients surviving the first 5 years. The worst survival rate occurs when the patient is treated only by surgery. In such cases, only 44 to 53% live above 5 years after the procedure [6].
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The long-term survival rates are low due to a characteristic late recurrence of the adenoid cystic carcinoma. Usually, around three-quarters of all tumors reappear within 10 years after treatment [7].
How does the tumor stage affect the success of adenoid cystic carcinoma treatment?
The stage of the tumor significantly affects the results of the treatment and survival.
Early-stage I and II tumors have a 5-year survival rate of 66 to 82%, while the advanced IV stage survival is 0 to 17% [8].
Moreover, tumors in advanced stages III and IV have more than six times more chance of regrowing, further affecting the outcome [9].
What is adenoid cystic carcinoma?
Adenoid cystic carcinoma is a rare malignant tumor, accounting for less than 3% of all head and neck carcinomas [10].
It primarily affects the salivary glands but can develop also in other glands [11, 12].
The adenoid cystic carcinoma occurs more frequently in women than men. The typical occurrence age is 50 and 60 years [13].
Adenoid cystic carcinoma is an aggressive tumor but has a slow growth speed [11].
It tends to spread along nerves and reappears locally after excision. Distant metastasis is also a characteristic of this carcinoma [11].
Why is adenoid cystic carcinoma dangerous?
Adenoid cystic carcinoma is dangerous due to its aggressiveness. The tumor invades its local environment, particularly the nerve tissues [14], making it difficult to treat it effectively.
Also, the carcinoma has a high recurrence, which can happen even years after initially successful therapy [10].
Another problem with adenoid cystic carcinoma is the high (20 to 50%) risk of metastasis. The tumor spreads to other tissues via the blood, particularly to bones and lungs [15].
The metastasis can appear even decades after the treatment of the primary carcinoma [16].
Additionally, adenoid cystic carcinoma often resists chemotherapy, making the therapy even more challenging [17].
Is there a definitive treatment for adenoid cystic carcinoma?
No - there isn't one definitive treatment for this cancer. Therefore, every adenoid cystic carcinoma case must be assessed best by a team of specialists.
However, the therapy usually involves surgery followed by radiotherapy [18, 19].
This combination is known to have the best treatment outcomes [18].
Chemotherapy is rarely used as adenoid cystic carcinoma is often resistant to this treatment [7].
At the moment, scientists are researching additional therapies for cancer, such as immunotherapy and target treatment. These therapies, though unavailable at the moment [20], can increase the effectiveness of adenoid cystic carcinoma in the future.