Sweat-gland tumours: a clinical review of cases in one centre over 20 years.

AIMS: Sweat-gland tumours (SGTs) are uncommon, but malignant varieties are very rare. We have added our data on 30 new cases seen at the Royal Marsden NHS Foundation Trust to the published literature, particularly concentrating on clinical issues. We include a literature review. MATERIALS AND METHODS: The Royal Marsden NHS Foundation Trust database was searched for cases of SGT from 1972. Data were collected on all cases, including patient demographics and tumour characteristics, treatment and outcome. RESULTS: Thirty cases were confirmed histologically to be SGTs. Fourteen were malignant, 15 benign and the degree of malignancy in one was histologically indistinguishable. Mean age was 55 years (64 for malignant, 47 for benign tumours). The 15 patients with benign tumours were almost all treated with complete excision. Those with local relapse underwent successful re-excision. Their 5-year disease-free survival was 78% and cause-specific survival was 100%. Twelve of the 14 malignant tumours had localised disease at diagnosis, one had nodal disease and one had metastatic tumour nodules. All except one were treated with wide local excision. The patient with nodal involvement also had a lymph-node dissection. Two received adjuvant radiotherapy to the tumour bed. One received a melphalan limb perfusion. Eight of the 14 had no relapse. Six had locoregional relapse, and four of these also developed distant metastases. Visceral disease was always fatal. Radiotherapy and chemotherapy at relapse were unsuccessful. Five-year disease-free survival was 45%, and cause-specific survival was 57%. CONCLUSION: These rare tumours should be treated initially with complete wide local excision. In malignant tumours, lymph-node involvement is a poor prognostic sign. Wide local excision remains the primary treatment. Adjuvant radiotherapy may be useful in high-risk cases.

Long-term follow-up of a randomised trial designed to determine the need for irradiation following conservative surgery for the treatment of invasive breast cancer.

Four hundred consecutive patients aged under 70 years diagnosed with a clinical T1 or T2 breast cancer were randomised to receive post-operative radiotherapy (n = 208) or not (n = 192), and monitored to record all local recurrences, distant recurrences and deaths for up to 20 years (median 13.7 years). All patients were treated by wide local excision and adjuvant therapy [estrogen receptor (ER) positive: tamoxifen; ER negative: CMF chemotherapy]. Kaplan-Meier and log-rank test methods were used to estimate and compare survival and recurrence. The 20-year Kaplan-Meier rates for local breast recurrence were 28.6% [95% confidence interval (CI) 19.6% to 37.6%] for radiotherapy and 49.8% (95% CI 40.8% to 58.9%). There was no significant difference between the two groups with regard to disease-free or overall survival. The hazard ratio for death among women who received radiation, as compared with those that did not, was 0.91 (95% CI 0.64-1.28; P = 0.59). Therefore, post-operative radiotherapy produced a clear-cut reduction in locoregional recurrence 0.45 (0.31-0.64; P = 0.0001), but did not influence the incidence of distant metastases or time of death. However, of the 119 patients who had a local recurrence, 51 (42.8%) had a distant recurrence, whereas of the 281 without local recurrence only 59 (21%) ever had a distant recurrence. A Cox's regression analysis with local recurrence as a time-dependent variable showed a risk ratio of 5.28 (P < 0.0001). This strong relationship is dependent on the intensity of post-treatment follow-up and investigation.

Estrogen-receptor-directed neoadjuvant therapy for breast cancer: results of a randomised trial using formestane and methotrexate, mitozantrone and mitomycin C (MMM) chemotherapy.

BACKGROUND: We wanted to determine whether neoadjuvant systemic chemoendocrine therapy guided by the estrogen receptor (ER) status of the primary breast cancer, followed by conventional surgery and/or radiotherapy, reduces local and distant recurrence and improves survival compared with adjuvant treatment given conventionally postoperatively. PATIENTS AND METHODS: Two hundred ten patients with primary breast cancer (T1-T4, N0, N1-2) were randomised to receive treatment with neoadjuvant chemoendocrine therapy or conventional post-operative chemoendocrine therapy. Systemic therapy was based on the estrogen receptor (ER) status of the primary tumour obtained by trucut core biopsy. ER-negative patients received MMM chemotherapy (methotrexate (30 mg/m2), mitozantrone (7 mg/m2) and mitomycin (7 mg/m2) three-weekly for three months and ER-positive patients who were premenopausal received goserelin (3.75 mg monthly), and post menopausal women formestane (250 mg every two weeks) over three months. RESULTS: With a minimum of five years follow-up, there is no evidence of any survival benefit from the pretreatment neoadjuvant therapy regimen, with five year overall survival being 79% +/- 4.7% (neoadjuvant) and 87% +/- 3.4% (adjuvant). Similarly, there was no apparent benefit in terms of disease-free survival. There was, however, a significant reduction in the incidence of distant metastases in responders (4 of 51; 8%) compared with non-responders (17 of 49; 35%) (P < 0.01). There was a reduction in the need for surgery in responding patients with T1 and T2 tumours, since 10 of 74 (14%) had no detectable residual tumour, without any apparent increase in the risk of local or distant recurrence. CONCLUSION: In this study neoadjuvant treatment with endocrine or chemotherapy provided no obvious survival benefit to women with breast cancer. However, it does allow avoidance of surgery in some cases. Also, the patients whose tumours respond to neoadjuvant systemic therapy have a lower incidence of distant metastases after five year follow-up compared to those whose tumours fail to respond.

A reduction in the requirements for mastectomy in a randomized trial of neoadjuvant chemoendocrine therapy in primary breast cancer.

BACKGROUND: A prospective randomised trial was undertaken to evaluate the role of neoadjuvant chemoendocrine therapy prior to surgery in primary operable breast cancer. PATIENTS AND METHODS: Three hundred nine women (median age 56 years, range 27-70) with primary operable breast cancer confirmed on fine needle aspiration (FNA) cytology were recruited to this study. They were treated with a combination of mitozantrone and methotrexate (+/- mitomycin-C) combined with tamoxifen (2MT). Patients received eight cycles of 2MT (four prior to surgery in the neoadjuvant group) and tamoxifen for five years with appropriate surgery and radiotherapy. The two groups were comparable for age, menopausal status, stage and surgical requirements. RESULTS: The clinical response rates to neoadjuvant therapy were as follows: 22% complete response (CR), 29% minimal residual disease (MRD), 33% partial response (PR), 15% no change (NC) and only two patients had clinical evidence of progressive disease. Surgical requirements were reduced from 31 patients (22%) of the adjuvant group having mastectomy to 14 (10%) in the neoadjuvant group (P < 0.003). At a median follow-up of 48 months (range 10-70 months) there is no statistically significant difference between the two groups in terms of local relapse, metastatic relapse or overall survival. Symptomatic and haematologic acute toxicity was low and similar for adjuvant and neoadjuvant therapy. CONCLUSION: This randomised trial has shown a significant reduction in the surgical requirements for mastectomy, after treatment with neoadjuvant chemoendocrine therapy, with no deterioration in local or distal relapse.

Assesssment of the effect of pretreatment with neoadjuvant therapy on primary breast cancer.

Patients with invasive cancer of the breast (T1-4, N0-2, M0) were assigned to pretreatment based on oestrogen receptor (ER) status; patients with ER-negative tumours received chemotherapy [mitozantrone, methotrexate and mitomycin C (MMM)] for 3 months, patients with ER-positive tumours underwent endocrine therapy [luteinising hormone releasing hormone (LHRH) agonist goserelin (leuprolide-premenopausal) or 4-hydroxyandrostenedione (formestane-post-menopausal)] for 3 months. Of the first 100 patients assessed at 3 months, 47 with ER-positive tumours had a 40.4% response (premenopausal 53.8%; post-menopausal 35%) and 53 with ER-negative tumours had a 60% response (premenopausal 57%; post-menopausal 63%). Patients with early breast cancer (T1/T2) had a complete clinical resolution in 41% (16/39) of cases after MMM and in 20% (7/35) of cases following endocrine therapy compared with 14% (2/14) advanced tumours (T3/T4) following MMM and (0/12) following endocrine therapy. However, in those patients achieving a complete clinical response, subsequent appropriate surgery showed that 16 of 19 patients (84%) had evidence of residual viable tumour on histological examination.

The importance of the resection margin in conservative surgery for breast cancer.

Eradication of breast cancer by wide local excision alone is not possible unless the clinical margins of excision exceeds 5 cm or a segmental mastectomy is performed, though recurrences may still occur after a segmental mastectomy. With inadequate excision radiotherapy to the breast is essential, but will not prevent local recurrence. In a prospective trial (1981 to 1990) to assess the value of radiotherapy to the breast when adjuvant therapy was administered, 418 patients treated by wide local excision and adjuvant chemotherapy (tamoxifen if oestrogen receptor-positive and CMF chemotherapy if oestrogen receptor-negative) were randomized to have loco-regional radiotherapy to the breast or not. At a minimum 5-year follow-up, the local recurrence rate in patients receiving radiotherapy was 13% compared to 35% in those not so treated. Local recurrence was strictly related to microscopic clearance in millimetres irrespective of clinical wide local excision, nodal, or menopausal status. Where, histologically, local excision was incomplete and patients received radiotherapy, the local recurrence rate was 17%. The criteria for wide local excision need to be strictly defined and histologically proven if post-operative radiotherapy is to achieve its effective function, that is the prevention of local recurrence. Radiotherapy cannot compensate for inadequate surgery.

Factors affecting acute skin toxicity in patients having breast irradiation after conservative surgery: a prospective study of treatment practice at the Royal Marsden Hospital.

The results are presented of a prospective study of acute skin toxicity in 197 patients with early stage breast cancer, who were treated by conservative surgery and postoperative radiotherapy. We have examined the factors determining the severity of the acute skin reaction with particular reference to the degree of dry or moist desquamation at the completion of treatment. One hundred and ten patients had treatment with radiotherapy alone. The remaining 87 received synchronous chemotherapy with breast irradiation, using either the 3M or the 2M regimen, consisting of mitoxantrone and methotrexate, with (3M) or without Mitomycin-C (2M). Patients were analysed according to both the severity and the site of the skin reaction, age, dose, dose variation across the central outline, treatment technique, beam energy, field separation and breast size. A univariate analysis of these results, which has been presented as an odds ratio of the likelihood of developing a moderate or severe reaction in comparison with those scored as mild, has shown that several factors are associated with an increase in the acute skin reaction. These include the use of the semi-supine technique (odds ratio (OR) = 7.3 (95% CI 3.7-14.6)), beam energy (60Co: 6-10 MV photons OR = 5.9 (95% CI 2.6-13.4)), field separation (> or = 20 cm: < 20 cm OR = 4.1 (95% CI 2.2-7.8)), dose variation across the central outline (> or = 10%: < 10% OR = 9.7 (95% CI 2.6-36.4)), inclusion of the axilla (OR = 4.6 (95% CI 2.4-8.9)), and bust size (bra cup size C and D: A and B OR = 4.6 (95% CI 2.7-11.9)). Using multivariate logistic regression, the technique of radiation delivery and bust size were shown to be independently significant variables affecting acute skin reaction. In view of the high correlation between variables (e.g. radiotherapy technique and beam energy) it is still not possible to specify with definite certainty which is the primary variable causing the skin reaction. However 20/57 (35%) of patients treated by the semisupine technique sustained a severe skin reaction, with > 10% dry or moist desquamation in the treatment field. This compares with only 6/140 (4%) patients treated by the supine method. A possible mechanism by which treatment using the semisupine technique may enhance acute toxicity is discussed. We conclude that there are both treatment and patient related factors that will increase the acute skin reaction after breast irradiation.

An acute toxicity study on the effects of synchronous chemotherapy and radiotherapy in early stage breast cancer after conservative surgery.

One hundred and ninety-seven patients with early stage breast cancer, who were treated initially with conservative surgery, were evaluated prospectively for acute toxicity after completing post-operative irradiation. Eighty-seven of these patients had synchronous chemotherapy with the 3M regimen (mitoxantrone, methotrexate and Mitomycin-C) during radiotherapy. The results indicate that patients receiving chemotherapy and radiotherapy (CRT) showed no significant difference in acute skin toxicity (AST) when compared with those treated with radiotherapy alone (RTO), with an odds ratio (OR = 0.6) and 95% confidence intervals (0.3-1.1) of developing either a moderate or severe, compared with a mild, skin reaction. Even after controlling for other confounding factors, such as treatment technique and beam energy, patients treated with the supine technique using 6-10 MV photons still displayed no significant difference in AST, with 12/74 (16%) patients in the CRT group and 14/66 (21%) in the RTO group developing a moderate or severe skin reaction (OR = 0.7 (95% CI 0.3-1.7)). Four of the 87 patients treated with CRT developed symptomatic acute radiation pneumonitis, three of whom were found to have > 3 cm of lung length on their simulator or check films. The volume of lung included within the treatment field was found to be statistically significant (P = 0.005) in predicting the onset of radiation pneumonitis in the CRT group. None of these patients has suffered any symptomatic late lung toxicity. We conclude that synchronous chemotherapy and radiotherapy, when using the 3M regimen, is feasible for patients having adjuvant treatment for early stage breast carcinoma and there is no significant increase in AST. However, it is associated with an increase in acute radiation pneumonitis when a significant volume of lung is included within the radiation treatment field.

The importance of the non-palpable lesion in women under 50, detected by mammography on self-referral for screening, symptoms or follow up.

Between 1.1.88 and 31.12.91, 349 consecutive patients had an x-ray localization excision of a non-palpable breast lesion less than 10 mm in diameter detected by 2-view mammography performed as a result of self-referral for screening (133), breast symptoms (164), or follow-up for breast disease (52). All lesions greater than 11 mm were excluded. 250 had benign and 99 (28%) had malignant lesions. 37 of 99 (37%) patients with malignancy were aged 49 or under. 133 patients requested screening, 33 (25%) had carcinoma of whom 11 (33%) were aged 49 or less. 164 patients presented with breast symptoms; 47 (29%) had cancer and 15 (32%) of these were aged 49 or less. 52 patients requested follow up for breast diseases including previous cancers, 19 (37%) had carcinoma of which 11 were 49 years or less (58%). 223 had microcalcifications, of which 68 (31%) were positive for cancer, and 126 had no microcalcification, of which 31 (25%) patients had cancer. The specific spiculate radiological lesions yielded 16 carcinomas in 31 cases (52%). Microcalcification was seen in 110 patients under 49 with 27 (25%) carcinomas detected. Microcalcification was a significant diagnostic criterion in the patients aged 49 or less, accounting for 27/37 (73%) patients. Dutal carcinoma in situ accounted for 18/37 (49%) in patients aged 49 or less, and 19/62 (31%) in patients over 50 years. Mammography should not be withheld from patients who are seeking screening, have symptoms, or who wish to be followed up, irrespective of age.

Three-dimensional kinematic analysis of baseball pitching in acceleration phase.

To examine the relationships of pitching performance to maximum external rotation of the shoulder and to time in the acceleration phase, 3 male baseball pitchers were tested using three-dimensional cinematography. Analysis indicated that increasing maximum external rotation of the shoulder at the very beginning of the acceleration phase would help to generate a higher pitching ball velocity since a greater linear and angular displacement could be used to accelerate the throwing forearm. Slowing the wrist action just before ball-release may be a key technique to increasing pitching velocity of the ball.

Measurement of S-phase fraction and ploidy in sequential fine-needle aspirates from primary human breast tumours treated with tamoxifen.

Sequential fine-needle aspirates (FNAs) for cytodiagnosis and flow cytometry were taken from 21 patients with primary breast carcinoma at intervals ranging from 1 to 3 months after the commencement of first-line tamoxifen therapy. Nine patients achieved a sustained complete or near complete response over a 3-9 month period. The tumour cells from seven out of nine of these patients were initially aneuploid, while the remaining two patients had diploid tumours. An analysis of sequential FNAs showed that, in three out of the seven aneuploid tumours, only benign epithelial cells could be detected by cytology in the post-tamoxifen sample. In the remaining six cases, including the two diploid tumours, there was no change in ploidy but a reduction in S-phase fraction (SPF) to approximately 50% of the pretreatment level. In all cases, these changes in ploidy or SPF were seen with a mean lead time of 4 months before the tumour had reached clinical complete remission. None of these patients have relapsed after a mean follow-up period of 18 months. The tumours of 12 patients achieved no more than a temporary partial response to primary tamoxifen therapy. In seven out of eight of these cases, which were all initially aneuploid, sequential FNAs during tamoxifen therapy revealed either an increase or no change in the SPF with the tumour remaining aneuploid. In the remaining four cases the tumours were all recorded as being diploid in the pretreatment sample. However, although three of these cases had a temporary partial response to tamoxifen, an aneuploid component was picked up in repeat sequential FNAs with a mean lead time of 5 months before clinical confirmation of eventual disease progression. We conclude that changes in ploidy and SPF detected by flow cytometry may predict initial response and the likelihood of relapse of breast tumours to tamoxifen before clinical changes become evident. These data justify a larger study.

Reaction force and EMG analyses of wheelchair transfers.

To examine how reaction forces and muscle activity change when transferring from a wheelchair to three different heights, six male able-bodied college students were tested. Analysis indicated that transferring to a lower seat position generated a greater vertical reaction force and required more muscle effort from triceps and posterior deltoid muscles. Transferring to a higher seat position resulted in a shift of the friction force from the anterior-posterior to the medial-lateral direction, and more biceps muscle effort was needed to perform the up-rightward movement. Transferring to a seat at the same height required less muscle effort from the upper extremities.

Prospective randomized trial of tamoxifen vs surgery in elderly patients with breast cancer.

Between 1982 and 1989, 200 patients aged 70 or over seen in one Breast Unit, who were considered to have a surgically resectable cancer of the breast were prospectively randomized to primary surgery or tamoxifen 20 mg per day. At a median follow-up of 6 years (range 3-11 years) and at the censoring date there were 61 first events in the tamoxifen group. Fifty three patients developed local relapse or progression of the cancer; three patients had simultaneous local progression or relapse and distant metastases. In addition a further five patients developed distant recurrence only. In the surgical arm there were 50 events. Thirty-six patients developed local recurrence only; eight had simultaneous local and distant recurrence. A further six patients developed distant metastases of which two subsequently developed local recurrence. There were 33 deaths in the tamoxifen group and 28 deaths in the surgical group of which 17 and 15, respectively were directly attributable to breast cancer. The disease-free interval did not differ between the two groups. Following treatment with tamoxifen, at the censoring date which was the date of last clinical examination or arbitrarily, the date of death, 39 patients had no evidence of relapse whereas in the surgical arm there were 50 patients who had no evidence of recurrence. Fifty-three patients in the tamoxifen arm had local relapse only and were available for crossover to surgery, 39 accepted surgery. Eight developed further local recurrence, 10 developed distant metastases and 21 remained free of disease. Thirty-six patients in the surgical group developed local relapse only and were available for crossover to tamoxifen. Thirty one accepted treatment with tamoxifen, 14 had progression of their local recurrence, seven developed distant metastases and 10 had no further recurrence. Thus in the tamoxifen group, 39 had no progression of their disease and a further 21 benefited from subsequent surgery: 60% in all. In the surgical group 50 had no recurrence of their disease and a further 10 benefited from subsequent tamoxifen therapy: 60% in all.

Gynaecological cytology and pelvic ultrasonography in patients with breast cancer taking tamoxifen compared with controls.

The objective of this study was to look at the effect of tamoxifen on the endometrium by comparing gynaecological cervical and endometrial cytology in breast cancer patients on tamoxifen for 3 years compared with controls. In addition, pelvic ultrasonography was employed to detect ovarian abnormalities and to measure endometrial thickness. Patients followed-up after primary surgical therapy for breast cancer were invited for gynaecological assessment consisting of clinical examination pelvic ultrasonography and a cervical smear and endometrial sampling. The patients taking tamoxifen (n = 49) has been on adjuvant hormone therapy for a minimum of 3 years. Control patients (n = 45) were also being followed-up for breast cancer. On examination the tamoxifen patients had very similar clinical findings to the control patients with regard to the cervix (normal in 84% of tamoxifen takers compared to 87% of controls). The uterus was clinically enlarged in eight patients on tamoxifen and in none of the control patients (P = 0.006) and only one ovarian cyst was clinically detectable in a patient taking tamoxifen. Pelvic ultrasonography between the two groups of patients was not statistically different (chi 2 test) and ovarian cysts were noted in nine patients from each group (tamoxifen patients 18% vs control patients 20%, n.s.). There was a highly significant difference in endometrial thickness in premenopausal patients (9.2 mm) compared with postmenopausal patients (6.4 mm, P = 0.001). There was also a suggestion that endometrial thickness was greater in tamoxifen treated patients (P = 0.08). In general, a greater proportion of patients taking tamoxifen had cervical and endometrial cells exhibiting hyperplastic nuclei, and in endocervical smears, this difference achieved statistical significance (Mann-Whitney test, P = 0.046). These findings show that a significantly increased proportion of patients taking tamoxifen had endocervical nuclear hyperplasia, and a trend towards increased endometrial thickness. These findings confirm that tamoxifen has mild oestrogenic activity. However, the lack of any difference in the incidence of dysplasia suggests that the carcinogenic potential of tamoxifen on the uterus is very low and the beneficial effects of tamoxifen as an adjuvant therapy for breast cancer outweighs its theoretical risks.

Use of silicone implants after wide local excision of the breast.

The appearance of the breast after wide local excision for carcinoma may be unsatisfactory. In 59 patients undergoing wide local excision a silicone prosthesis was inserted into the cavity at the time of primary surgery. Assessment of the cosmetic result was performed after 12 months by questionnaire and clinical examination. Four prostheses were removed within 1 year because of infection (two patients), wound breakdown (one) and pain (one). Seven prostheses were subsequently removed because of severe capsular contraction. Capsular contraction was more common in patients who had received radiotherapy. Only 23 patients found the results of the implant acceptable or satisfactory. The immediate use of intramammary implants after wide local excision is currently associated with a poor cosmetic result, and the problem of the distorted breast after such excision requires continued attention.

Comparison of cholesterol in habitually high and low active school-age children.

While risk-factor screening programs for coronary artery disease have been effective among adults, few programs are available for school-age children. 31 children were screened (16 active and 15 inactive) for cholesterol levels. The physically active group had a nonsignificantly lower mean which may reflect the small sample.

A randomised prospective trial of surgical against medical tetracycline pleurodesis in the management of malignant pleural effusions secondary to breast cancer.

Malignant pleural effusion is a frequent complication of metastatic breast cancer leading to a significant degree of morbidity. Drainage of the effusion by thoracocentesis and pleurodesis with tetracycline as the sclerosing agent is an established means of symptomatic relief in these patients. To determine whether the efficacy of tetracycline pleurodesis is improved by surgical rather than medical drainage and instillation of sclerosant, 34 patients were prospectively randomised to a trial comparing the two treatment modalities, of whom 29 were evaluable for response. The total failure rate of primary pleurodesis was 13.4%, the rate of recurrence of effusion within the first month was 24%, and only 1 patient (3.4%) required repeat aspiration in that time period. There was no significant difference in the rate of recurrence or reaspiration of effusion between the two treatment groups. Although the overall survival time from treatment of effusion is significantly longer in the surgical treatment group than in the medical treatment group (P = 0.03), this is likely to be due to factors other than the method of treating the effusion. We conclude that surgical tetracycline pleurodesis has no advantage over medical tetracycline pleurodesis.

Adjuvant aminoglutethimide for postmenopausal patients with primary breast cancer: analysis at 8 years.

PURPOSE: The study purpose was to evaluate aminoglutethimide (AG) as adjuvant therapy in patients with primary node-positive breast cancer in a randomized double-blind placebo-controlled trial. PATIENTS AND METHODS: In a multicenter trial, 354 postmenopausal women with early breast cancer and histologically confirmed positive axillary lymph nodes were randomized after surgery to received aminoplac. Patients were prescribed either AG 250 mg four times per day and hydrocortisone 20 mg twice per day or placebos of identical appearance for 2 years. RESULTS: After a median follow-up of 8.1 years, there has been no overall benefit for AG in terms of either event-free survival or overall survival (OS). However, the results are consistent with interim analyses with a significantly improved event-free survival for patients who received AG for up to 4 years, although this benefit subsequently disappears. Similarly, there is an improved OS for patients who received AG for up to 4 years, but this also subsequently disappears. There was a marginal advantage for estrogen receptor (ER)-positive patients who received AG (n = 74; P = .054). There was no difference in the sites of relapse. There was a significant increase in toxicity for patients who received AG. CONCLUSION: The lack of survival benefit with long-term follow-up for AG may indicate that aromatase inhibitors have less of an impact on early breast cancer than tamoxifen and may imply different biologic mechanisms of action.

Lactic acidosis. A presentation of metastatic breast cancer arising in pregnancy.

Lactic acidosis B is a rare metabolic complication of malignancy. It usually is associated with advanced and extensive metastatic disease. The authors report a case in which lactic acidosis was the presenting feature of a previously undiagnosed case of metastatic breast cancer in a pregnant woman and that resolved with successful antineoplastic treatment. The authors review the likely cause and management of the condition.