Cancer Treatment Today » Radiation

Post-mastectomy Radiation

M Levin, MD — Mon, 20 Aug 2012 19:42:59 +0000

The rationale for post-mastectomy radiation(PMRT) is to decrease the chance that cells left behind will regrow in the remaining skin or tissue after mastectomy. Although this is not a common complication, when it ocurrs, it can be devastating. Although the concern is understandable, post-mastectomy radiation tends to be overused in theUSA. For example, women who have stage I or II disease with spread to no more than three lymph nodes and who did not undergo radiation therapy, have the overall growth rate in the same general area rate of just 2.3% at 10 years. A 2005 meta-analysis looked at randomized trials conducted between 1964 and 1984. The analysis determined that post-mastectomy radiation in these women resulted not only in about a 66% reduction in locoregional recurrence compared with no radiation, but also about a 5% survival advantage. However, the overall recurrence rate in those studies ranged from 20% to 25%, much higher than observed in the present.

Certainly, locoregional PMRT is recommended for women with an advanced primary tumour (tumour size 5 cm or greater, or tumor invasion of the skin, pectoral muscle or chest wall) or with 4 or more positive axillary lymph nodes, because the risk of regrwth is significant. However, the role of PMRT in women with 1 to 3 positive axillary lymph nodes is unclear. Locoregional PMRT is generally not recommended for women who have tumors that are less than 5 cm in diameter and who have negative axillary nodes. Other patient, tumor and treatment characteristics, including age, histologic grade, iinvasion of lymph and neural stands, hormone receptor status, number of axillary nodes removed, extension of cancer out of the capsule of lymph nodes in the armpit extension and surgical margin status, may affect loco-regional control, but their use in specifying additional indications for PMRT is currently unclear.

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Post-mastectomy Radiation – pro

M Levin, MD — Mon, 20 Aug 2012 19:38:34 +0000

Post-mastectomy radiation tends to be overused in the USA. For example, women who have stage I or II disease with spread to no more than three lymph nodes and who did not undergo radiation therapy, have the overall locoregional recurrence rate of just 2.3% at 10 years. A 2005 meta-analysis looked at randomized trials conducted between 1964 and 1984. The analysis determined that postmastectomy radiation in these women resulted not only in about a 66% reduction in locoregional recurrence compared with no radiation, but also about a 5% survival advantage. However, the overall recurrence rate in those studies ranged from 20% to 25%, much higher than observed in the present.

Certainly, locoregional PMRT is recommended for women with an advanced primary tumour (tumour size 5 cm or greater, or tumour invasion of the skin, pectoral muscle or chest wall) or with 4 or more positive axillary lymph nodes. However, the role of PMRT in women with 1 to 3 positive axillary lymph nodes is unclear. Locoregional PMRT is generally not recommended for women who have tumours that are less than 5 cm in diameter and who have negative axillary nodes. Other patient, tumour and treatment characteristics, including age, histologic grade, lymphovascular invasion, hormone receptor status, number of axillary nodes removed, axillary extracapsular extension and surgical margin status, may affect locoregional control, but their use in specifying additional indications for PMRT is currently unclear.

Pauline T. Truong,Clinical practice guidelines for the care and treatment of breast cancer: 16. Locoregional post-mastectomy radiotherapy CMAJ April 13, 2004 vol. 170 no. 8

Sharma R, et al “Present day locoregional recurrence rates (LRR) in patients with T1 and T2 breast cancer (BC) with zero and one to three lymph node (LN) metastases following mastectomy without radiation” SSO 2010; Abstract 47

Taylor ME, Haffty BG, Rabinovitch R, Arthur DW, Halberg FE, Strom EA, White JR, Cobleigh MA, Edge SB, Expert Panel on Radiation Oncology-Breast. ACR Appropriateness Criteria® postmastectomy radiotherapy. [online publication]. Reston (VA): American College of Radiology (ACR); 2008. 17 p. [96 references]

Postmastectomy Radiotherapy: Clinical Practice Guidelines of the American Society of Clinical OncologyJournal of Clinical Oncology, Vol 19, Issue 5 (March), 2001: 1539-1569

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Hyperfractionated radiotherapy in head and neck cancer – pro

M Levin, MD — Thu, 21 Jun 2012 22:12:47 +0000

Hyperfrationated radiotherapy has been extensively studied, both in the treatment of head and neck cancer and in other cancer types. Hyperfractionated radiotherapy (multiple fractions per day) yields higher rates of acute toxicity compared with conventional radiotherapy (one fraction per day, five days per week). Data on the incidence and severity of late complications associated with hyperfractionation are incomplete. It is premature to conclude that hyperfractionation with dose escalation does not increase late tissue complications.
Although the improvements in loco-regional control and survival are promising, longer follow-up and more complete information on late complications will be needed to meaningfully compare these results to those achieved with concomitant chemoradiation in locally advanced squamous cell carcinoma of the head and neck.
A recent guideline concluded that conclusions regarding loco-regional control are limited by the quality of the published data. To date, only three of seven randomized controlled trials have provided convincing evidence of improved loco-regional control with hyperfractionation compared with conventional radiotherapy. In one of these three studies, improved loco-regional control was accompanied by an increase in overall survival. Two other randomized controlled trials have documented improved overall survival with hyperfractionation, but both studies have been criticized for failing to report complete data. Another emtaanalysis, hosever, concluded that altered fractionated radiotherapy improves survival in patients with head and neck squamous cell carcinoma and that comparison of the different types of altered radiotherapy suggests that hyperfractionation has the greatest benefit. The issue requires more study and the propsoed treatment should be considered experimental.

Head and Neck Cancer Disease Site Group. Mackenzie RG, Hodson DI, Browman GP, Zuraw L. Hyperfractionated radiotherapy for locally advanced squamous cell carcinoma of the head and neck [full report]. Toronto (ON): Cancer Care Ontario (CCO); 2003 Jan [online update]. 13 p. (Practice guideline report; no. 5-6b). [22 references]

Lancet. 2006 Sep 2;368(9538):843-54. Links

Overgaard J, Audry H, Ang KK, Saunders M, Bernier J, Horiot JC, Le Maître A, Pajak TF, Poulsen MG, O’Sullivan B, Dobrowsky W, Hliniak A, Skladowski K, Hay JH, Pinto LH, Fallai C, Fu KK, Sylvester R, Pignon JP;Hyperfractionated or accelerated radiotherapy in head and neck cancer: a meta-analysis.Bourhis J, Meta-Analysis of Radiotherapy in Carcinomas of Head and neck (MARCH) Collaborative Group.Comment in:
Lancet. 2006 Nov 25;368(9550):1867-8; author reply 1868.
Lancet. 2006 Nov 25;368(9550):1867; author reply 1868.
Lancet. 2006 Sep 2;368(9538):819-21.
Republished in:
Clin Otolaryngol. 2007 Apr;32(2):119.