Bone metastases and breast cancer

CA 15.3 with Urinary Calcium Excretion is Useful in the Diagnosis and Monitoring of Bone Metastases from Breast Cancer

Serum levels of breast carcinoma antigen (CA 15.3) and urinary calcium excretion (UCa) were determined in 73 patients with breast cancer: 36 without bone metastases (stage I-IV) and 37 with bone metastases. The patients in the latter group were further investigated at 2,4 and 6 months from the start of treatment. Both markers showed significant elevations in the group with bone metastases (CA 15.3: P = 1.0×10–6, UCa: P = 8.6×10–9). The bone metastasis index (BMI), which represents the combination of the markers, had better diagnostic efficacy (90%) than CA 15.3 alone (84%) or UCa alone (82%).

During treatment of bone metastasis, the longitudinal levels of the markers showed a highly significant association with the therapeutic response assessed by the UICC criteria. For identifying progression of disease, the diagnostic efficacy of CA 15.3, UCa and a combination of both, the so-called Biochemical Index of Response (BIR), was 65%, 70% and 79%, respectively, at two months and 89%, 84% and 92% at four months.

Application of the tandem, CA 15.3 with UCa, was very useful for the detection of bone metastases and the prediction of response to therapy.

Hypercalcaemia: historical perspectives and present management

Hypercalcaemia is a well-recognised complication in patients with several types of cancer. Since determination of the serum calcium has become routine particularly in hospital patients, the identification of hypercalcaemia associated with cancer has increased. Cancer is the most common cause of hypercalcaemia arising in hospitalised patients, and overall approximately one-third of all patients presenting with hypercalcaemia have an underlying cancer. In Western countries, the common causes of hypercalcaemia are cancers of the lung and breast. The median survival of patients with hypercalcaemia and cancer is only 5 weeks, indicating that in many patients treating hypercalcaemia may not achieve prolonged survival, even if symptoms are palliated. The clinical presentations of hypercalcaemia are well known, encompassing gastrointestinal, neurological, cardiovascular and renal symptoms. Management approaches have evolved over the past few years from hydration and use of drugs that promote calcium excretion to new treatments that inhibit bone resorption.

Selection of patients with breast cancer for routine follow-up bone scans

Routine radionuclide bone scans have not been considered cost-effective for the routine follow-up after treatment of primary breast cancer. However subgroups of patients exist in whom early relapse in the skeleton is likely and this study examines again the role of the bone scan in routine follow-up. Serial radionuclide bone scans were performed every 6 months during the first 2 years of follow-up of 560 patients with breast cancer. Tumor characteristics which predict early relapse in bone were identified and the scan conversion rate from negative to positive determined for each prognostic group. A total of 199 (28%) of patients have relapsed, 50 (9%) with first recurrence in bone within two years of diagnosis. All were identified on the bone scan with a median lead time of 4 months over radiological evidence of bone involvement. The overall scan conversion rate was 2.8%. This was significantly higher in poor prognosis patients with T4 tumours (6.3%), more than four involved axillary lymph nodes (6.1%) and inoperable tumours (6.5%), than in good prognosis patients with T1 tumours (1.1%), negative axillary lymph node involvement (1.2%) or well-differentiated ductal grade tumours (1.1%). We do not recommend routine bone scans in the follow-up of all patients with breast cancer. In patients with a good prognosis after primary treatment they cannot be considered cost-effective. However, in those with features which predict early recurrence in the skeleton the frequency of scan conversion is sufficient to justify serial bone scanning during the first two years of follow-up.

Treatment of bone metastases from breast cancer with (3-amino-1-hydroxypropylidene)-1,1-bisphosphonate (APD)

Twenty-eight patients with progressive symptomatic bone metastases from breast cancer received (3-amino-1-hydroxypropylidene)-1,1-bisphosphonate (APD) 30 mg in 500 ml of 0.9% saline infused over 2 h every 14 days. No other systemic therapy for breast cancer was prescribed. All patients had progressed on at least one previous systemic treatment. APD was continued until the disease progressed. Patients were assessed for objective response by the UICC criteria. In addition, subjective response was determined by a pain questionnaire. Radiological evidence of bone healing with sclerosis of lytic disease (UICC partial response) was seen in 4 patients. The median duration of response was 10 months. Eleven patients had stable disease for at least 3 months (median 5 months) and 9 progressed. Symptomatic response occurred in 9 patients and 12 reported an improvement in quality of life. Treatment was tolerated well with no significant toxicity. In conclusion, long-term inhibition of bone destruction is possible with APD therapy alone and both subjective and objective responses are seen.

Biochemical prediction of response of bone metastases to treatment

Assessment of response of skeletal metastases to systemic therapy is currently dependent on radiological evidence of bone healing. We have performed a prospective study of additional response criteria in patients with progressive bone metastases from breast cancer. Changes in these potential markers of response were correlated with the radiological response and the time to treatment failure (TTF). Successful systemic therapy typically led to a transient increase in osteoblast activity ('flare'), a reduction in osteoclast activity and symptomatic improvement. After 1 month a greater than 10% rise in serum osteocalcin (BGP) and alkaline phosphatase bone isoenzyme (ALP-BI) and a greater than 10% fall in urinary calcium excretion were seen in 14/16 patients with radiographic evidence of bone healing (UICC partial responders). In comparison similar biochemical changes at 1 month were seen in only 4/20 patients with progressive disease (P less than 0.001). The predictive value and diagnostic efficiency (DE) of changes at 1 month in biochemical measurements and symptom score has been calculated. The combination of a greater than 10% rise in ALPBI and BGP and a greater than 10% fall in urinary calcium excretion had a DE of 89% for discriminating response from progression, 88% for response from non-response (progressing + no change patients), and 76% for TTF of greater than 6 months from TTF of less than 6 months. Serum calcium, tartrate resistant acid phosphatase (TRP), urinary hydroxyproline excretion and bone scan changes were unhelpful in discriminating between patient groups. Independent confirmation is needed, but our results suggest there are reliable alternatives to plain radiography in the early assessment of response of bone metastases to treatment.

Osteocalcin: a potential marker of metastatic bone disease and response to treatment

Serum osteocalcin (BGP) is an osteoblast product that probably reflects the rate of bone formation. It is a potential marker of skeletal metastases and, to investigate this, BGP was measured by radioimmunoassay in the serum of normal subjects and patients with breast or prostate cancer. Significantly higher levels were found in patients with metastatic bone disease in comparison to both normal subjects (P less than 0.001) and patients with non-metastatic cancer (P less than 0.05 for breast cancer and less than 0.001 for prostate cancer). The range of values was wide. Levels were higher in sclerotic than lytic bone metastases (P less than 0.01) and lower in patients with hypercalcaemia (P less than 0.001). Serial measurements of BGP were made in 53 patients with skeletal metastases from breast cancer receiving systemic therapy. At 1 month BGP rose by greater than 0.5 ng/ml in 15/16 responding patients compared with 7/23 patients with progressive disease (P less than 0.01). Responding patients also showed a rise in the bone isoenzyme of alkaline phosphatase and a paradoxical deterioration in the bone scan appearance, both reflecting a flare in osteoblast activity. The early increase in responding patients was followed by a gradual decrease over subsequent months as the osteoblast reaction induced by systemic therapy subsided. We conclude that BGP measurements reflect a wide variability of bone formation rates in metastatic bone disease. Bone formation was usually increased, particularly when metastases were sclerotic in appearance, but in patients with hypercalcaemia the low BGP levels suggest uncoupling of bone resorption and formation. Serial measurements of BGP may be useful in monitoring response to treatment.

Does parasternal irradiation reduce thoracic vertebral metastases in breast cancer?

A review of 197 patients with bone metastases from breast carcinoma was undertaken to assess the effect of adjuvant parasternal irradiation on the distribution of those metastases. A total of 128 patients (Group I) received radiation. The control group consisted of 69 patients (Group II) who did not receive adjuvant radiation. The dose absorbed by the mid-thoracic vertebrae (T3 to T8) varied from 10 Gy in 3 weeks to 20 Gy in 4 weeks. The distribution of bone metastases was analyzed at the initial development in the 197 patients. Repeat assessments (X ray/scans) were available for analysis in 132 patients. Patients in Group I had less metastases from T3 to T8: 37/128 (29%), vs 30/69 (43.5%) for patients in Group II: (chi 2 = 3.62; p less than 0.10). For the 132 patients with serial assessments, the difference at last evaluation was more significant: 45/86 (52%) in Group I, vs 36/46 (78%) in Group II: (chi 2 = 7.44; p less than 0.01). The data shows that patients receiving low-dose exit beam irradiation from the parasternal field have fewer mid-thoracic bone metastases. Potential implications are discussed.

The response evaluation of bone metastases in mammary carcinoma. The value of radiology, scintigraphy, and biochemical markers of bone metabolism

The correlation between response of metastatic bone lysis and bone pain, various biochemical markers of bone metabolism, and radiological and scintigraphic findings was investigated in 49 women with breast cancer included in a calcitonin supportive therapy trial. All patients had dominant skeletal disease and were on stable systemic treatment (cytotoxic or hormonal) for a least 6 months before the first response evaluation. Bone pain correlated poorly with treatment response. Changes in sclerotic metastases did not show any apparent relation to changes in lytic lesions. A correlation between bone scans and lytic activity on radiographs was found. The absolute level of biochemical bone markers did not correlate with treatment response, but seemed instead to reflect the rate of bone turnover. The relative level of bone markers with respect to baseline showed better correlation to treatment response. The best conventional marker of disease activity was urinary hydroxyproline/creatinine. Propeptide of Type III procollagen (PIIINP), a novel marker reflecting collagen turnover, promises to be at least as sensitive as hydroxyproline. Stable and regressing patients had the same prognosis and significantly longer survival than progressors.

Bone metastases: pathogenesis, treatment, and rationale for use of resorption inhibitors

Tumors in bone are usually metastatic, with breast, prostate, and lung tumors accounting for more than 80 percent of clinically manifest lesions. Untreated, such metastases can produce the symptoms that most concern cancer patients--pain, pathologic fractures, and paralysis through epidural cord compression. Recent advances in the understanding of the metastatic cascade and the regulation of bone formation and resorption provide unique therapeutic approaches for prevention and treatment of these lesions. This article reviews the prevalence, distribution, diagnosis, and treatment of metastatic cancer in the skeleton, as well as the processes involved in the development of such metastases, the local mediators responsible for some of the destructive changes in bone, and their pathologic results. In addition to considering some of the conventional therapeutic approaches, a rationale for the use of bone resorption inhibitors, such as the diphosphonates (bisphosphonates), is presented for the prevention and amelioration of the pathologic consequences of skeletal metastases.

The clinical course of bone metastases from breast cancer

All patients with carcinoma of the breast seen in this Unit since 1970 were reviewed to study the incidence, prognosis, morbidity and response to treatment of bone metastases. The biological characteristics of the primary tumour were compared in patients relapsing first in bone or liver. Sixty-nine percent of patients dying with breast cancer had bone metastases and bone was the commonest site of first distant relapse. Bone relapse was more common in receptor positive or well differentiated (grade 1) tumours. The median survival was 24 months in those with disease apparently confined to the skeleton compared with 3 months after first relapse in liver. Ten percent of patients with breast cancer developed hypercalcaemia. All had metastatic disease and 85% had widespread skeletal involvement. Fifteen percent of patients with disease confined to the skeleton developed hypercalcaemia. The response in bone to primary endocrine therapy, and chemotherapy, was apparently less than the overall response achieved. A large proportion had apparently static disease reflecting the insensitivity of the UICC assessment criteria. The duration of survival in these patients was similar to responding patients, suggesting a tumour response may occur in the absence of discernable radiological evidence of healing.