Factors influencing the response and survival of patients with liver metastases from breast cancer receiving OK-432-combined adoptive immunotherapy

Exploring factors related to metastasis free survival in breast cancer patients using Bayesian cure models

BACKGROUND

Breast cancer is a fatal disease and the most frequently diagnosed cancer in women with an increasing pattern worldwide. The burden is mostly attributed to metastatic cancers that occur in one-third of patients and the treatments are palliative. It is of great interest to determine factors affecting time from cancer diagnosis to secondary metastasis.

MATERIALS AND METHODS

Cure rate models assume a Poisson distribution for the number of unobservable metastatic-component cells that are completely deleted from the non-metastasis patient body but some may remain and result in metastasis. Time to metastasis is defined as a function of the number of these cells and the time for each cell to develop a detectable sign of metastasis. Covariates are introduced to the model via the rate of metastatic-component cells. We used non-mixture cure rate models with Weibull and log-logistic distributions in a Bayesian setting to assess the relationship between metastasis free survival and covariates.

RESULTS

The median of metastasis free survival was 76.9 months. Various models showed that from covariates in the study, lymph node involvement ratio and being progesterone receptor positive were significant, with an adverse and a beneficial effect on metastasis free survival, respectively. The estimated fraction of patients cured from metastasis was almost 48%. The Weibull model had a slightly better performance than log-logistic.

CONCLUSIONS

Cure rate models are popular in survival studies and outperform other models under certain conditions. We explored the prognostic factors of metastatic breast cancer from a different viewpoint. In this study, metastasis sites were analyzed all together. Conducting similar studies in a larger sample of cancer patients as well as evaluating the prognostic value of covariates in metastasis to each site separately are recommended.

Docetaxel: a new active agent in the therapy of metastatic breast cancer

Breast cancer is the most common malignancy in women, accounting for about 18% of female cancers, and over half a million new cases are diagnosed worldwide each year. Its incidence increases with age and is currently rising. Although the increased availability of screening programs has allowed earlier detection and treatment of primary breast cancers, many patients relapse with metastases after apparently successful treatment of their primary tumor and over 15,000 women in the UK and about 50,000 in the USA die from advanced disease each year. The natural course of breast cancer is very variable even after the development of metastases, and depends on a variety of tumor characteristics and prognostic factors. This is reflected in the large number of treatments currently employed. However, despite this wide choice and considerable research over the years, treatment of metastatic breast cancer (MBC) prolongs average survival times only slightly. Current therapy is aimed at achieving a balance between producing maximal tumor shrinkage to produce the most effective possible palliation of symptoms, and minimizing adverse effects. Anticancer chemotherapy is the preferred option in patients who do not respond to hormones, those with hormone-independent tumors, those with aggressive breast cancer subtypes. A variety of anticancer chemotherapy regimens, using both single and combined agents, have been shown to be effective in achieving tumor regression in MBC. Anthracyclines (doxorubicin, epirubicin) are the most active of the established monotherapies, typically producing response rates of 50-60% during initial (first-line) treatment for metastatic disease, but being effective in fewer than 25% of patients requiring second-line therapy. The drawbacks of anthracyclines include dose-limiting cumulative cardiotoxicity and the development of resistant tumor clones after the use of anthracyclines for adjuvant or first-line therapy, especially if subsequent courses are required within a year. The success of these established chemotherapeutic agents depends greatly on the number and location of metastatic sites. Lymph node and soft tissue secondaries tend to respond well, while visceral metastases (especially in the liver) carry a particularly poor prognosis despite treatment. The outlook for patients with metastases involving more than two organ systems is also bleak. Although some patients can live for years with metastatic disease, the average survival time in patients with MBC is 18-24 months, while in those with liver metastases, life expectancy averages only 6 months. High-dose anticancer chemotherapy with granulocyte-colony stimulating factor (G-CSF) or autologous bone marrow transplantation has allowed the dose intensity of anthracyclines to be increased, and has improved the response rate to about 70% in selected patients with MBC. However, this approach has not been proven to improve survival, involves the risk of greater toxicity and drug-related mortality, and patients with reduced clearance of anthracyclines due to hepatic dysfunction from liver metastases may not be suitable candidates. A number of new anticancer agents have also recently been introduced in an attempt to improve on the performance and avoid the tolerability problems associated with anthracyclines. Among these, antitubulin agents (taxoids and vinorelbine) have shown highly promising activity in MBC. This paper reviews the preclinical, phase I and phase II data for one taxoid, docetaxel. Docetaxel (Taxotere) belongs to the taxoid class of cytotoxic agents, the development of which began more than 20 years ago. In 1971, paclitaxel (Taxol) was identified as the active compound of the crude extract of the bark of the Pacific Yew tree Taxus brevifolia. However, at that time the development of paclitaxel was hampered because of the limited source of the drug and difficulties with isolation, extraction and formulation. The second active taxoid, docetaxel, was isolated by Potier et al. in 1986. Docetaxel is prepared from a non-cytotoxic precursor, extracted from the needles of the European Yew tree Taxus baccata, that is condensed with a chemically-synthesized side-chain. As the docetaxel precursor is freely available because of the regenerating capacity of the needles the development of docetaxel has thus been rapid.

Locoregional immuno(bio)therapy for liver metastases

Despite advances in locoregional chemotherapy, treatment of metastatic liver tumors remains a challenge. Since the liver is the largest organ of the reticuloendothelial system, locoregional immunotherapy would be a reasonable approach for the management of hepatic metastases. Indeed, various immunological approaches have been explored. Regional infusion of cytokines such as interleukin 2 (IL-2) or tumor necrosis factor-alpha (TNF-alpha) through the hepatic artery or the portal vein has been combined with chemotherapy and demonstrated to be better than chemotherapy alone. Locoregional adaptive immunotherapy (AIT) using lymphokine-activated killer (LAK) cells or tumor-infiltrating lymphocytes (TIL) has also been tried with rather disappointing responses. Addition of immunostimulants such as OK-432 to AIT increased clinical responses. Recently, several new approaches have emerged to improve the outcome of locoregional immunotherapy. Embolization of melanoma metastatic to the liver with a granulocyte-macrophage colony-stimulating factor (GM-CSF)/ethiodized oil emulsion resulted in control of liver metastases, as well as development of significant immune responses in remote extrahepatic metastases. A gene therapy designed to introduce foreign major histocompatibility complex (MHC) molecules in colorectal metastases has proven to be a safe and feasible approach. Larger scale clinical trials are mandatory to define the role of locoregional immunotherapy for metastatic tumors in the liver.

Prognostic significance of liver metastases as first site of generalisation in patients with breast cancer--a retrospective analysis

Of 672 patients with metastatic breast cancer, 24 evaluable patients with primary liver metastases were analysed with regard to their prognostic variables and survival. In 50% of these patients, liver metastases were found within the first 8.5 months after the diagnosis of breast cancer. The median survival of 10 months (range 0-60+ months) was extremely unfavourable. The median survival of hormone-receptor-positive patients (11 months) was significantly longer than that of patients with hormone-receptor-negative tumours (4 months) (P = 0.025). Patients with elevated lactate dehydrogenase (LDH), glutamic-oxaloacetic transaminase (GOT) (> 50 U/I), or bilirubin levels at diagnosis had a significantly shorter median survival than patients with normal laboratory parameters (P = 0.001, P = 0.047, and P = 0.056, respectively). This retrospective study confirms the short survival time for breast cancer patients with liver metastases as initial site of relapse. Hormone-receptor status and the laboratory parameters LDH, GOT, and bilirubin were identified as important prognostic factors for survival.

OK-432-combined adoptive immunotherapy as a prognostic factor in peritoneal metastasis from gastric cancer

Prognostic factors, such as preoperative status, intraoperative findings, and postoperative treatments, were evaluated in 61 patients with peritoneal metastasis from gastric cancer treated in our facility between 1979 and 1991. Since 1986, 23 patients have been treated with OK-432-combined adoptive immunotherapy (AIT). OK-432-combined AIT is a sequential treatment via a catheter inserted into the abdominal cavity, using a streptococcal preparation, OK-432, followed by the transfer of lymphocytes cultured with T cell growth factor and sonicated tumor extract. A univariate analysis showed that six factors consisting of: (1) age, (2) resection of primary lesion, (3) grade of peritoneal metastasis or serosal invasion, (4) chemotherapy, (5) OK-432, and (6) OK-432-combined AIT influenced survival. The survival of the patients given OK-432-combined AIT (median survival time; MST = 7.5 months) was significantly (P = 0.0267) longer than that of those not receiving OK-432-combined AIT (MST = 4.3 months). A multivariate analysis showed that the most significant factors associated with survival were chemotherapy, resection of the primary lesion, and OK-432-combined AIT. Since these three factors are all therapeutic procedures, the use of combination therapy including OK-432-combined AIT is thus expected to prolong the survival of gastric cancer patients with peritoneal metastasis.

Bone metastasis as a prognostic factor in breast cancer patients with liver metastasis given OK-432-combined adoptive immunotherapy via the hepatic artery

The outcome in 31 patients with liver metastases from breast cancer given OK-432-combined adoptive immunotherapy via the hepatic artery was analyzed. Patients received intraarterial OK-432, a streptococcal preparation, followed by the transfer of autologous lymphocytes cultured with autologous tumor extract and interleukin-2 for 9-13 days. Liver lesions were evaluable in 11 of the 12 patients with bone metastasis (group A) and in 16 of the 19 patients without bone metastasis (group B). Complete response (CR) in the liver was attained in 8 patients in group A, but in only 1 in group B (p < 0.01). In group A, radiological features of all metastatic foci of bone improved after CR in the liver. Moreover, the median survival time (MST) of group A (20 months) was longer (p = 0.06) than that of group B patients with extra-hepatic metastasis (n = 12; MST = 6 months), while group B patients with liver metastasis alone (n = 7) showed a MST similar to that of group A. Thus, loco-regional immunotherapy via the hepatic artery was found to be useful in controlling both liver and bone metastasis from breast cancer. Moreover, in breast cancer patients with liver metastasis, bone metastasis appears to be a prognostic factor associated with good response to this immunotherapy.

Relationship between immunological parameters and survival of patients with liver metastases from breast cancer given immuno-chemotherapy

We treated 33 patients with liver metastases from breast cancer by immuno-chemotherapy including adoptive cell transfer between 1987 and 1992. In this study, we examined the change of immunological parameters in the peripheral blood lymphocytes and interleukin-2 (IL-2)-cultured lymphocytes, in primary vs. metastatic breast cancer patients and before vs. after treatment. Moreover, we examined their correlation with therapeutic response and survival after treatment. The immunological parameters used were in vitro natural killer cell activity (% lysis of K562), in vitro autologous tumor-killing activity (% lysis against autologous freshly isolated tumor cells), and proliferation of lymphocytes stimulated with IL-2 and autologous sonicated tumor extract antigen in mixed culture (IL-2-enhanced MLTR). When compared with primary breast cancer patients, patients with liver metastases showed a significant decrease in % lysis of K562 and autologous tumor cells. After treatment, the stimulation index in IL-2-enhanced MLTR increased significantly from the pretreatment level and correlated with survival after treatment. Moreover, non-specific immunological parameters (performance status, lymphocyte count, and transferred cell count and proliferation rate of cultured lymphocytes) were significantly associated with response and prognosis.