Differentiated thyroid cancer. Impact of adjuvant external radiotherapy in patients with perithyroidal tumor infiltration (stage pT4)

J Farahati, C Reiners, M Stuschke, S P Müller, G Stüben, W Sauerwein, H Sack
Cancer 1996 January 1, 77 (1): 172-80

BACKGROUND: The role of adjuvant external radiotherapy in the survival of patients with differentiated thyroid cancer (DTC) is controversial. To our knowledge, no attempt has been undertaken thus far to assess the impact of this therapy with respect to the papillary and follicular types of thyroid cancer as separate entities.

METHODS: Between 1979 and 1992, 238 patients with differentiated papillary thyroid cancer (PTC) and follicular thyroid cancer (FTC) with Stage pT4 have been treated and followed in our clinic. One hundred sixty-nine patients free of metastases at the final staging, which was performed after the second radioiodine therapy, were included in this study. The standard treatment comprised total thyroidectomy, ablative radioiodine therapy, and thyroid-stimulating hormone-suppressive therapy with levothyroxin. Ninety-nine patients free of disease after the final staging received additional external radiotherapy to the neck (with a dose of 50-60 Gy), whereas the remaining 70 patients were treated with the standard treatment protocol only. Distributions of age, sex, and follow-up time were comparable in both irradiated and nonirradiated groups. Multivariate analysis of the influence of age, sex, histologic subtype, and lymph node status as well as of external radiotherapy on the time to first locoregional and distant failure (LDF), and the time to locoregional recurrence (LR), was accomplished using Cox's proportional hazard model.

RESULTS: In patients with DTC, external radiotherapy was a predictive factor for improvement of both LR (P = 0.004) and locoregional and distant failure (P = 0.0003). When the time to first locoregional and distant failure was calculated separately for patients with PTC and FTC, there was a significant difference in the PTC group in favor of irradiated patients (P = 0.0001), whereas there was no effect of external radiotherapy in the FTC group (P = 0.38). Further analyses disclosed that this effect was significantly present only in patients with PTC and lymph node involvement (P = 0.002), whereas those without lymph node involvement did not benefit from an additional adjuvant radiotherapy (P = 0.27). Because none of the patients younger than age 40 years died due to the disease nor had progressive disease during follow-up, we reassessed our results in patients older than age 40 years. The effect of external radiotherapy could be confirmed in this subgroup of patients (P = 0.0009) and in the subgroup of lymph node positive patients older than age 40 years with invasive PTC (P = 0.01).

CONCLUSIONS: In addition to total thyroidectomy, treatment with radioiodine, and TSH-suppressive therapy with thyroid hormone, adjuvant external radiotherapy improves the recurrence-free survival in patients older than age 40 years with invasive PTC and lymph node involvement.

Full Text Links

Find Full Text Links for this Article


You are not logged in. Sign Up or Log In to join the discussion.

Trending Papers

Remove bar
Read by QxMD icon Read

Save your favorite articles in one place with a free QxMD account.


Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"