CTS and Breast Cancer
There are a variety of areas of common ground between CTS and breast cancer. Firstly it should be noted that both CTS and breast cancer are common diseases in older women and thus they will inevitably occur together by chance some of the time. There are however some special considerations.
Drug treatment for breast cancer and CTS
Many breast cancers are responsive to female hormones - their continued growth is partially driven by hormones - and treatment therefore often involves manipulation of your hormonal balance to try to reduce the drive to the cancer. This is mainly now achieved through drug treatment with the best known drugs being:
Tamoxifen (Trade names Nolvadex, Istubal, Valodex but now out of patent) - an oestrogen antagonist
Exemestane (Trade name Aromasin) - an aromatase inhibitor which blocks the conversion of androgens into oestrogens. After the menopause most of your oestrogen comes from conversion of androgens, not from the ovaries
Anastrozole (Trade name Arimidex) - another aromatase inhibitor widely used in the UK
Other marketed aromatase inhibitors include Letrozole (Femara), Vorozole (Rivizor), Formestane (Lentaron), Fadrozole (Afema) and Testolactone (Teslac). Exemestane has been noted for some time to cause CTS in a significant number of women who take it. In a study comparing women treated with tamoxifen and exemestane, 0.6% of 2338 subjects on tamoxifen developed CTS while in the exemestane group the figure was 2.8% of 2319 subjects with the highest incidence of CTS occurring about 6 months after commencing treatment with the drug (Mieog 2012). 69% of these cases were treated surgically but in general CTS was not considered to be a reason for stopping treatment with exemestane.
Although they have been less extensively studied it seems quite possible that other aromatase inhibitors will also cause an increase in the incidence of CTS.
CTS and lymphoedema
Surgical treatment of breast cancer often involves removal or irradiation of the lymph nodes in the armpit. These structures are part of one system which drains excess fluid from the arm and interference with these can result in persistent and troublesome swelling of the limb - a condition known as lymphoedema. This raises two CTS questions:
Does lymphoedema predispose to CTS?
The answer to this one is not known for certain but one might expect that the accumulation of fluid in the limb might increase the pressure in the carpal tunnel and there is some evidence to suggest that CTS is commoner after this kind of breast surgery.
In a 2001 study of 250 patients who had undergone axillary dissection for breast cancer 143 patients (57%) provided follow-up data and 15 of these (10%) had been given a post operative diagnosis of CTS (31% reported hand numbness or tingling though). However only 47 reported post-operative oedema. The degree of overlap between the three reported events of - 1) arm swelling 2) numbness/tingling and 3) a firm diagnosis of CTS - is not clear from the paper, and there is no matched control group for comparison (Bozentka 2001).
Another study looked at 90 patients (Ganel 1979) and found CTS in 28% of subjects after surgery. 8% of these patients had CTS on the unoperated side. They also felt that 28% of these patients had evidence of brachial plexus entrapment. Again there is no true control group.
A third study (Stubblefield 2015) examined 19 patients (38 arms) with lymphoedema and CTS and looked for any association between either presence/absence of lymphoedema and CTS in individual arms, or between the severity of lymphoedema and the severity of CTS. They found no evidence that lymphoedema predisposes to CTS.
Does Investigation or treatment of CTS aggravate lymphoedema?
Testing - I have found one website which recommends avoiding needle EMG in arms with lymphoedema. This does not appear to be an evidence based recommendation but in most cases of CTS needle examination is not needed. There seems to be no good reason not to carry out nerve conduction studies on these arms, though where there is gross swelling it may make the results less reliable. If you use compression bandaging for lymphoedema you will usually have to remove it for a few minutes for nerve conduction studies. A recent study (Stubblefield 2015) found no instances of either infection or worsening of lymphoedema after needle EMG examination.
Steroid injection - There is no published data indicating any increased risk from local steroid injection for CTS in the presence of lymphoedema. Some people recommend antibiotic cover when injecting into a limb with lymphoedema but again this does not seem to be based on any hard evidence
Surgery - There are now two papers demonstrating that hand surgery can be carried out safely in the presence of lymphoedema.
In the first, 52 patients were operated without significant complications, despite the use of a pneumatic tourniquet (Assmus 2004). The full paper is in German and I have not as yet had it translated but the English abstract is as follows:
PURPOSE
Following surgery for breast cancer, an increased risk is assumed for development or worsening of lymphedema following hand surgery procedures. The aim of this study was to find out whether surgery performed with exsanguination using a pneumatic tourniquet has any disadvantages under these circumstances. There might result consequences for patients' information of possible risks as well as for performance of hand surgical procedures.
METHOD:
52 patients who had undergone mastectomy were included in the study. In 47 of these, axillary lymph node biopsy or dissection had been performed. 41 patients had been advised not to allow measurement of blood pressure, drawing of blood or surgery to that arm. Surgical release of the retinaculum flexorum by using local anesthesia and exsanguination for a maximum of ten minutes was performed at an average of 7.5 (range from 1 - 26) years after the breast operation.
RESULTS:
Following release of the carpal ligament a temporary swelling of the arm or hand was found in four patients, which persisted for 2 - 3 months in one patient and disappeared within one week in the others. Three patients suffered from moderate lymphedema before surgery. It was unaffected by hand surgery in two patients and only temporarily worsened for several days in another patient. In all patients, neurological symptoms (paresthesia, numbness and pain) improved completely. Other complications, particularly infections, were not observed.
CONCLUSIONS:
1. Exaggerated information of patients with breast surgery in their history does not seem to be indicated in minor hand surgical procedures. 2. The hand surgeon should inform the patients preoperatively that there may occur a transient swelling which can be avoided by loose dressings and early functional training. Using a pneumatic tourniquet has no adverse effect on existing lymphedema in short lasting procedures. 3. Since patients after mastectomy and/or axillary dissection often complain about arm pain and paraesthesia, not only brachial plexus pathology but also a carpal tunnel syndrome must be considered.
In the second study (Gunnoo 2015), 32 women with lymphoedema and carpal tunnel syndrome had surgery and the effect on the lymphoedema was measured in terms of lymphoedema volume. There was no significant change in the swelling at an avrage 33 months follow-up after surgery, though there was a short term increase during the first year after surgery which then settled again. All 32 patients experienced satisfactory resolution of their CTS symptoms. The operations were fairly standard, open carpal tunnel decompression, using a tourniquet to control bleeding, and without any prophylactic antibiotic cover.
Revision date - 21st August 2015
