Splenectomy before tumor inoculation prolongs the survival time of cachectic mice

Splenectomy has opposite effects on the growth of primary compared with metastatic tumors in a murine colon cancer model

The spleen is a key source of circulating and tumor-infiltrating immune cells. However, the effect of splenectomy on tumor growth remains unclear. At 3 weeks after splenectomy, we subcutaneously injected LuM1 cells into BALB/c mice and evaluated the growth of primary tumors and lung metastases at 4 weeks after tumor inoculation. In addition, we examined the phenotypes of immune cells in peripheral blood by using flow cytometry and in tumor tissue by using multiplex immunohistochemistry. The growth of primary tumors was reduced in splenectomized mice compared with the sham-operated group. Conversely, splenectomized mice had more lung metastases. Splenectomized mice had fewer CD11b+cells, especially monocytic MDSCs (CD11b+Gr-1neg-lowLy6chigh), and NK cells (CD49b+CD335+). The proportion of NK cells was inversely correlated with the number of lung metastases. In splenectomized mice, the density of CD3+ and granzyme B+ CD8+ T cells was increased, with fewer M2-type macrophages in primary tumors, but NK cells were decreased markedly in lung. Splenectomy concurrently enhances T cell-mediated acquired immunity by reducing the number of monocytic MDSCs and suppresses innate immunity by decreasing the number of NK cells. Splenectomy has opposite effects on primary and metastatic lesions through differential regulation on these two immune systems.

Trabectedin and Lurbinectedin Extend Survival of Mice Bearing C26 Colon Adenocarcinoma, without Affecting Tumor Growth or Cachexia

Trabectedin (ET743) and lurbinectedin (PM01183) limit the production of inflammatory cytokines that are elevated during cancer cachexia. Mice carrying C26 colon adenocarcinoma display cachexia (i.e., premature death and body wasting with muscle, fat and cardiac tissue depletion), high levels of inflammatory cytokines and subsequent splenomegaly. We tested whether such drugs protected these mice from cachexia. Ten-week-old mice were inoculated with C26 cells and three days later randomized to receive intravenously vehicle or 0.05 mg/kg ET743 or 0.07 mg/kg PM01183, three times a week for three weeks. ET743 or PM01183 extended the lifespan of C26-mice by 30% or 85%, respectively, without affecting tumor growth or food intake. Within 13 days from C26 implant, both drugs did not protect fat, muscle and heart from cachexia. Since PM01183 extended the animal survival more than ET743, we analyzed PM01183 further. In tibialis anterior of C26-mice, but not in atrophying myotubes, PM01183 restrained the NF-κB/PAX7/myogenin axis, possibly reducing the pro-inflammatory milieu, and failed to limit the C/EBPβ/atrogin-1 axis. Inflammation-mediated splenomegaly of C26-mice was inhibited by PM01183 for as long as the treatment lasted, without reducing IL-6, M-CSF or IL-1β in plasma. ET743 and PM01183 extend the survival of C26-bearing mice unchanging tumor growth or cachexia but possibly restrain muscle-related inflammation and C26-induced splenomegaly.

Myeloid PTEN deficiency impairs tumor-immune surveillance via immune-checkpoint inhibition

Tumor-host interaction is determined by constant immune surveillance, characterized by tumor infiltration of myeloid and lymphoid cells. A malfunctioning or diverted immune response promotes tumor growth and metastasis. Recent advances had been made, by treating of certain tumor types, such as melanoma, with T-cell checkpoint inhibitors. This highlights the importance of understanding the molecular mechanisms underlying the crosstalk between tumors and their environment, in particular myeloid and lymphoid cells. Our aim was to study the contribution of the myeloid PI3K/PTEN-signaling pathway in the regulation of tumor-immune surveillance in murine models of cancer. We made use of conditional PTEN-deficient mice, which exhibit sustained activation of the PI3K-signaling axis in a variety of myeloid cell subsets such as macrophages and dendritic cells (DCs). In colitis-associated colon cancer (CAC), mice deficient in myeloid PTEN showed a markedly higher tumor burden and decreased survival. We attributed this observation to the increased presence of immune-modulatory conventional CD8α(+) DCs in the spleen, whereas other relevant myeloid cell subsets were largely unaffected. Notably, we detected enhanced surface expression of PD-L1 and PD-L2 on these DCs. As a consequence, tumoricidal T-cell responses were hampered or redirected. Taken together, our findings indicated an unanticipated role for the PI3K/PTEN-signaling axis in the functional regulation of splenic antigen-presenting cells (APCs). Our data pointed at potential, indirect, tumoricidal effects of subclass-specific PI3K inhibitors, which are currently under clinical investigation for treatment of tumors, via myeloid cell activation.

Splenectomy inhibits non-small cell lung cancer growth by modulating anti-tumor adaptive and innate immune response

It has been shown that inhibitors of the immune system reside in the spleen and inhibit the endogenous antitumor effects of the immune system. We hypothesized that splenectomy would inhibit the growth of relatively large non-small lung cancer (NSCLC) tumors by modulating the systemic inhibition of the immune system, and in particular Myeloid Derived Suppressor Cells (MDSC). The effect of splenectomy was evaluated in several murine lung cancer models. We found that splenectomy reduces tumor growth and the development of lung metastases, but only in advanced tumors. In immune-deficient NOD-SCID mice the effect of splenectomy on tumor growth and metastatic spread disappeared. Splenectomy significantly reduced the presence of MDSC, and especially monocytic-MDSC in the circulation and inside the tumor. Specific reduction of the CCR2+ subset of monocytic MDSC was demonstrated, and the importance of the CCL2-CCR2 axis was further shown by a marked reduction in CCL2 following splenectomy. These changes were followed by changes in the macrophages contents of the tumors to become more antitumorigenic, and by increased activation of CD8⁺ Cytotoxic T-cells (CTL). By MDSC depletion, and adoptive transfer of MDSCs, we demonstrated that the effect of splenectomy on tumor growth was substantially mediated by MDSC cells. We conclude that the spleen is an important contributor to tumor growth and metastases, and that splenectomy can blunt this effect by depletion of MDSC, changing the amount and characteristics of myeloid cells and enhancing activation of CTL.

The importance of tissue environment surrounding the tumor on the development of cancer cachexia

The relationship between host factors and cancer cachexia was investigated. A single cell clone (clone 5 tumor) established from colon 26 adenocarcinoma by limiting dilution cell cloning methods was employed to eliminate the inoculation site-dependent differences in the composition of cell clones. Clone 5 tumor did not provoke manifestations of cancer cachexia when inoculated in subcutaneous tissue. However, when inoculated in the gastrocnemius muscle, the peritoneal cavity or the thoracic cavity of CD2F1 male mice, typical manifestations of cancer cachexia were observed in all groups of mice with intergroup variations. The blood levels of various cytokines, chemokines and hormones were increased but with wide intergroup variations. Analyses by stepwise multiple regression models revealed that serum interleukin-10 was the most significant factor associated with manifestations of cancer cachexia, suggesting the possible involvement of mechanisms similar to cancer patients suffering cancer cachexia. White blood cells, especially neutrophils, seemed to have some roles on the induction of cancer cachexia, because massive infiltrations and an increase in peripheral blood were observed in cachectic mice bearing clone 5 tumors. The amount of malonyl-CoA in liver correlated with manifestations of cancer cachexia, however the mRNA levels of spermidine/spermine N-1 acetyl transferase (SSAT) (of which overexpression has been shown to provoke manifestations similar to cancer cachexia) were not necessarily associated with cancer cachexia. These data suggest that the induction of cancer cachexia depends on the environment in which the tumor grows and that the infiltration of host immune cells into the tumor and the resultant increase in inflammation result in the production of cachectic factors, such as cytokines, leading to SSAT activation. Further, multiple factors likely mediate the mechanisms of cancer cachexia. Finally, this animal model was suitable for the investigation of the mechanisms involved in cachexia of cancer patients.

Long-term risks after splenectomy among 8,149 cancer-free American veterans: a cohort study with up to 27 years follow-up

Although preservation of the spleen following abdominal trauma and spleen-preserving surgical procedures have become gold standards, about 22,000 splenectomies are still conducted annually in the USA. Infections, mostly by encapsulated organisms, are the most well-known complications following splenectomy. Recently, thrombosis and cancer have become recognized as potential adverse outcomes post-splenectomy. Among more than 4 million hospitalized USA veterans, we assessed incidence and mortality due to infections, thromboembolism, and cancer including 8,149 cancer-free veterans who underwent splenectomy with a follow-up of up to 27 years. Relative risk estimates and 95% confidence intervals were calculated using time-dependent Poisson regression methods for cohort data. Splenectomized patients had an increased risk of being hospitalized for pneumonia, meningitis, and septicemia (rate ratios=1.9-3.4); deep venous thrombosis and pulmonary embolism (rate ratios=2.2); certain solid tumors: buccal, esophagus, liver, colon, pancreas, lung, and prostate (rate ratios =1.3-1.9); and hematologic malignancies: non-Hodgkin lymphoma, Hodgkin lymphoma, multiple myeloma, acute myeloid leukemia, chronic lymphocytic leukemia, chronic myeloid leukemia, and any leukemia (rate ratios =1.8-6.0). They also had an increased risk of death due to pneumonia and septicemia (rate ratios =1.6-3.0); pulmonary embolism and coronary artery disease (rate ratios =1.4-4.5); any cancer: liver, pancreas, and lung cancer, non-Hodgkin lymphoma, Hodgkin lymphoma, and any leukemia (rate ratios =1.3-4.7). Many of the observed risks were increased more than 10 years after splenectomy. Our results underscore the importance of vaccination, surveillance, and thromboprophylaxis after splenectomy.

Expanding spectrum of the association between Type 1 Gaucher disease and cancers: a series of patients with up to 3 sequential cancers of multiple types--correlation with genotype and phenotype

In Gaucher disease (GD), inherited deficiency of lysosomal glucocerebrosidase due to mutations in GBA1 gene results in accumulation of glucosylceramide in tissue macrophages, systemic macrophage activation, and a complex multisystemic phenotype. We and others have reported an increased risk of multiple myeloma and other malignancies in non-neuronopathic Type 1 GD (GD1). Here, we describe a subset of GD1 patients with multiple malignancies. In our cohort of 403 patients with GD1, nine patients (2.2%) developed two or three different types of cancers either consecutively or simultaneously. Patients were characterized by age at diagnosis of GD1, GBA1 genotype, disease severity, age at cancer diagnosis, enzyme replacement therapy (ERT) status, and splenectomy status. Of the nine patients, six developed two types of malignancies and three had three cancers each. Overall, the hematologic malignancies comprised lymphoma/leukemia (4) and multiple myeloma (4). Nonhematologic malignancies included colon (2), lung (2), thyroid (2), and prostate cancer (1). Of the seven patients who received ERT, the first cancer was diagnosed before initiation of ERT in all but one. Asplenic patients were more likely to have single or multiple cancers compared with patients with intact spleens (P < 0.0072 and P < 0.0203, respectively). Our data strengthen the association of GD1 and cancer and suggest that patients may be at risk of developing multiple malignancies. We found an association between splenectomy and multiple cancers in GD1. It will be of interest to determine whether timely ERT and declining rates of splenectomy will translate into declining rates of multiple and single cancers.

Complications of splenectomy

Surgical removal of the spleen, splenectomy, is a procedure that has significantly decreased in frequency as our understanding of the infectious complications of the asplenic state increased. The full spectrum and details of splenic function, however, have yet to be fully outlined. As a result, our comprehension of the long-term consequences of splenectomy remains incomplete. We review the evidence relating to the effects of splenectomy on infection, malignancy, thrombosis, and transplantation. Perhaps the best-defined and most widely understood complication of splenectomy is the asplenic patient's susceptibility to infection. In response to this concern, novel techniques have emerged to attempt to preserve splenic function in those patients for whom surgical therapy of the spleen is necessary. The efficacy of these techniques in preserving splenic function and staving off the complications associated with splenectomy is also reviewed in this article.

Inhibition of cyclooxygenase-2 by celecoxib reverses tumor-induced wasting

There have been a number of reports suggesting inhibition of prostaglandin production may impact tumor-mediated wasting and levels of associated humoral factors such as hypercalcemia. These reductions were achieved using traditional nonsteroidal anti-inflammatory drugs (NSAIDs), which are often contraindicated in cancer patients. This is especially true during chemotherapeutic regimens due to concerns of bleeding from gastrointestinal and hematopoietic toxicities associated with inhibition of the housekeeping cyclooxygenase enzyme COX-1. Here, we report that celecoxib, one of the new class of selective COX-2 inhibitors, has the potential to reverse tumor-mediated wasting and associated humoral factors such as interleukin (IL)-6 and hypercalcemia in preclinical models of cachexia. Tumor bearing mice in late stage cachexia regained weight within days of the start of celecoxib treatment. Two models were tested. The first was the Colon 26 (Col26) syngeneic murine model that induces high levels of circulating IL-6 and hypercalcemia. The second was the human head and neck 1483 HNSCC xenograft model, which is less inflammatory and produces less prostaglandin than Col26. Despite the observation that no significant impact on tumor growth was observed between vehicle and celecoxib-treated animals over the course of the studies, celecoxib rapidly reversed weight loss in both cachectic models. With the added safety of celecoxib over traditional NSAIDs, these results suggest a possible therapeutic use for celecoxib for treating tumor-mediated wasting.

The impact of splenectomy on outcomes after resection of pancreatic adenocarcinoma

BACKGROUND

Splenectomy at the time of resection of esophageal, gastric, or colon cancer has been correlated with inferior longterm survival. No such effect has yet been demonstrated for pancreatic cancer.

STUDY DESIGN

Patients undergoing resection of pancreatic adenocarcinoma with curative intent at Memorial Sloan-Kettering Cancer Center between October 1983 and October 1995 were identified from a prospective clinical database. The impact of splenectomy on hospital stay and survival was calculated with univariate and multivariate nonparametric methods.

RESULTS

Of 332 patients undergoing pancreatectomy, 326 with confirmed local or regional disease only formed the study cohort. Of these, 37 underwent concomitant splenectomy (11.4%). Splenectomy was significantly correlated with distal or total pancreatectomy, primary location in tail or body, portal vein invasion or resection, a larger maximal tumor diameter, and an operative blood loss of greater than 2,000 mL. Death or need for reoperation was not affected by splenectomy. Patients undergoing splenectomy had a higher median transfusion requirement (3 versus 1; p = 0.002). The median postoperative length of stay was 15 days regardless of splenectomy. At a median followup of 16.3 months (36.4 months for surviving patients), the median actuarial survival was 12.2 months with splenectomy versus 17.8 months without splenectomy (p<0.005). On multivariate analysis, splenectomy emerged as an independent factor predictive of decreased postoperative survival (p = 0.02), in addition to pathologic lymph node status (p = 0.0002), tumor diameter (p = 0.0004), and tumor differentiation (p = 0.007). Tumor location within the pancreas and the type of pancreatectomy were not independent prognostic factors influencing survival.

CONCLUSIONS

After pancreatectomy for pancreatic cancer, splenectomy has no significant measurable impact on postoperative recovery, but has a negative influence on longterm survival independent of disease-related factors. Unless required because of tumor proximity or invasion, splenectomy should be avoided in the operative treatment of exocrine pancreatic cancer at any location.