Perioperative IFN-alpha to avoid surgically induced immune suppression in colorectal cancer patients

The Potential for Cancer Immunotherapy in Targeting Surgery-Induced Natural Killer Cell Dysfunction

Natural Killer (NK) cells are granular lymphocytes of the innate immune system that are able to recognize and kill tumor cells without undergoing clonal selection. Discovered over 40 years ago, they have since been recognized to possess both cytotoxic and cytokine-producing effector functions. Following trauma, NK cells are suppressed and their effector functions are impaired. This is especially important for cancer patients undergoing the removal of solid tumors, as surgery has shown to contribute to the development of metastasis and cancer recurrence postoperatively. We have recently shown that NK cells are critical mediators in the formation of metastasis after surgery. While research into the mechanism(s) responsible for NK cell dysfunction is ongoing, knowledge of these mechanisms will pave the way for perioperative therapeutics with the potential to improve cancer outcomes by reversing NK cell dysfunction. This review will discuss mechanisms of suppression in the postoperative environment, including hypercoagulability, suppressive soluble factors, the expansion of suppressive cell populations, and how this affects NK cell biology, including modulation of cell surface receptors, the potential for anergy, and immunosuppressive NK cell functions. This review will also outline potential immunotherapies to reverse postoperative NK dysfunction, with the goal of preventing surgery-induced metastasis.

Combining surgery and immunotherapy: turning an immunosuppressive effect into a therapeutic opportunity

Background

Cancer surgery is necessary and life-saving. However, the majority of patients develop postoperative recurrence and metastasis, which are the main causes of cancer-related deaths. The postoperative stress response encompasses a broad set of physiological changes that have evolved to safeguard the host following major tissue trauma. These stress responses, however, intersect with cellular mediators and signaling pathways that contribute to cancer proliferation.

Main

Previous descriptive and emerging mechanistic studies suggest that the surgery-induced prometastatic effect is linked to impairment of both innate and adaptive immunity. Existing studies that combine surgery and immunotherapies have revealed that this combination strategy is not straightforward and patients have experienced both therapeutic benefit and drawbacks. This review will specifically assess the immunological pathways that are disrupted by oncologic surgical stress and provide suggestions for rationally combining cancer surgery with immunotherapies to improve immune and treatment outcomes.

Short conclusion

Given the prevalence of surgery as frontline therapy for solid cancers, the emerging data on postoperative immunosuppression and the rapid development of immunotherapy for oncologic treatment, we believe that future targeted studies of perioperative immunotherapy are warranted.

Dysfunctional Natural Killer Cells in the Aftermath of Cancer Surgery

The physiological changes that occur immediately following cancer surgeries initiate a chain of events that ultimately result in a short pro-, followed by a prolonged anti-, inflammatory period. Natural Killer (NK) cells are severely affected during this period in the recovering cancer patient. NK cells play a crucial role in anti-tumour immunity because of their innate ability to differentiate between malignant versus normal cells. Therefore, an opportunity arises in the aftermath of cancer surgery for residual cancer cells, including distant metastases, to gain a foothold in the absence of NK cell surveillance. Here, we describe the post-operative environment and how the release of sympathetic stress-related factors (e.g., cortisol, prostaglandins, catecholamines), anti-inflammatory cytokines (e.g., IL-6, TGF-β), and myeloid derived suppressor cells, mediate NK cell dysfunction. A snapshot of current and recently completed clinical trials specifically addressing NK cell dysfunction post-surgery is also discussed. In collecting and summarizing results from these different aspects of the surgical stress response, a comprehensive view of the NK cell suppressive effects of surgery is presented. Peri-operative therapies to mitigate NK cell suppression in the post-operative period could improve curative outcomes following cancer surgery.

Surgical Stress Abrogates Pre-Existing Protective T Cell Mediated Anti-Tumor Immunity Leading to Postoperative Cancer Recurrence

Anti-tumor CD8+ T cells are a key determinant for overall survival in patients following surgical resection for solid malignancies. Using a mouse model of cancer vaccination (adenovirus expressing melanoma tumor-associated antigen (TAA)-dopachrome tautomerase (AdDCT) and resection resulting in major surgical stress (abdominal nephrectomy), we demonstrate that surgical stress results in a reduction in the number of CD8+ T cell that produce cytokines (IFNγ, TNFα, Granzyme B) in response to TAA. This effect is secondary to both reduced proliferation and impaired T cell function following antigen binding. In a prophylactic model, surgical stress completely abrogates tumor protection conferred by vaccination in the immediate postoperative period. In a clinically relevant surgical resection model, vaccinated mice undergoing a positive margin resection with surgical stress had decreased survival compared to mice with positive margin resection alone. Preoperative immunotherapy with IFNα significantly extends survival in surgically stressed mice. Importantly, myeloid derived suppressor cell (MDSC) population numbers and functional impairment of TAA-specific CD8+ T cell were altered in surgically stressed mice. Our observations suggest that cancer progression may result from surgery-induced suppression of tumor-specific CD8+ T cells. Preoperative immunotherapies aimed at targeting the prometastatic effects of cancer surgery will reduce recurrence and improve survival in cancer surgery patients.

Attacking Postoperative Metastases using Perioperative Oncolytic Viruses and Viral Vaccines

Surgical resection of solid primary malignancies is a mainstay of therapy for cancer patients. Despite being the most effective treatment for these tumors, cancer surgery has been associated with impaired metastatic clearance due to immunosuppression. In preclinical surgery models and human cancer patients, we and others have demonstrated a profound suppression of both natural killer (NK) and T cell function in the postoperative period and this plays a major role in the enhanced development of metastases following surgery. Oncolytic viruses (OV) were originally designed to selectively infect and replicate in tumors, with the primary objective of directly lysing cancer cells. It is becoming increasingly clear, however, that OV infection results in a profound inflammatory reaction within the tumor, initiating innate and adaptive immune responses against it that is critical for its therapeutic benefit. This anti-tumor immunity appears to be mediated predominantly by NK and cytotoxic T cells. In preclinical models, we found that preoperative OV prevents postoperative NK cell dysfunction and attenuates tumor dissemination. Due to theoretical safety concerns of administering live virus prior to surgery in cancer patients, we characterized safe, attenuated versions of OV, and viral vaccines that could stimulate NK cells and reduce metastases when administered in the perioperative period. In cancer patients, we observed that in vivo infusion with oncolytic vaccinia virus and ex vivo stimulation with viral vaccines promote NK cell activation. These preclinical studies provide a novel and clinically relevant setting for OV therapy. Our challenge is to identify safe and promising OV therapies that will activate NK and T cells in the perioperative period preventing the establishment of micrometastatic disease in cancer patients.

A mouse tumor model of surgical stress to explore the mechanisms of postoperative immunosuppression and evaluate novel perioperative immunotherapies

Surgical resection is an essential treatment for most cancer patients, but surgery induces dysfunction in the immune system and this has been linked to the development of metastatic disease in animal models and in cancer patients. Preclinical work from our group and others has demonstrated a profound suppression of innate immune function, specifically NK cells in the postoperative period and this plays a major role in the enhanced development of metastases following surgery. Relatively few animal studies and clinical trials have focused on characterizing and reversing the detrimental effects of cancer surgery. Using a rigorous animal model of spontaneously metastasizing tumors and surgical stress, the enhancement of cancer surgery on the development of lung metastases was demonstrated. In this model, 4T1 breast cancer cells are implanted in the mouse mammary fat pad. At day 14 post tumor implantation, a complete resection of the primary mammary tumor is performed in all animals. A subset of animals receives additional surgical stress in the form of an abdominal nephrectomy. At day 28, lung tumor nodules are quantified. When immunotherapy was given immediately preoperatively, a profound activation of immune cells which prevented the development of metastases following surgery was detected. While the 4T1 breast tumor surgery model allows for the simulation of the effects of abdominal surgical stress on tumor metastases, its applicability to other tumor types needs to be tested. The current challenge is to identify safe and promising immunotherapies in preclinical mouse models and to translate them into viable perioperative therapies to be given to cancer surgery patients to prevent the recurrence of metastatic disease.

In vivo suppression of NK cell cytotoxicity by stress and surgery: glucocorticoids have a minor role compared to catecholamines and prostaglandins

Most in vitro and ex-vivo studies indicate a profound suppression of NK cell cytotoxicity (NKCC) by glucocorticoids; while catecholamines and prostaglandins were reported both to suppress and to enhance NKCC. However, methodological considerations hinder our ability to deduce from these findings to the impact of endogenous release of these factors on in vivo levels of NKCC and their implications to NK-dependent resistance to pathologies in living humans or animals. Here we used an in vivo approach that sensitively and specifically reflects NKCC in living F344 rats, based on lung clearance of NK-sensitive tumor cells (MADB106), and based on comparing effects between NK-intact and NK-depleted rats. To study the role of corticosterone, epinephrine, and prostaglandins, we administered these factors to rats, or antagonized their endogenous release following different stress paradigms or surgery. The results indicated that endogenous or exogenous elevated corticosterone levels can suppress in vivo NKCC levels, but only under some conditions, and mostly secondarily to the NK-suppressing impact of epinephrine. Specifically, corticosterone-induced NKCC suppression occurred (i) only under prolonged, but not short exposure to stress, and mainly in males; (ii) was smaller than the prominent impact of epinephrine; (iii) was mostly ascribed to corticosterone-induced potentiation of the effects of epinephrine or/and prostaglandins; and (iv) was completely abolished through antagonizing epinephrine or/and prostaglandins. Overall, these findings markedly limit the significance of stress/surgery-induced corticosterone release in the in vivo suppression of NKCC, and highlight the blockade of epinephrine or/and prostaglandins as effective and clinically feasible approaches to overcome such immuno-suppressive effects.

Intestinal obstruction due to primary intestinal melanoma in a patient with a history of rectal cancer resectioning: A case report

The vast majority of the cases of intestinal melanomas are metastatic lesions, originating from an occult primary cutaneous or ocular lesion, whereas primary small intestinal melanomas are extremely rare. This is a rare case of primary small intestinal malignant melanoma with intestinal obstruction in a patient with a prior history of rectal cancer resection. The patient was admitted for abdominal pain and obstipation. Following an overall inspection, the patient was subjected to surgical treatment and a small intestinal tumor was removed. The histopathological examination of the lesion revealed a diffuse neoplastic infiltration involving the entire thickness of the intestinal mucosa. The neoplastic cells exhibited marked atypia, pleomorphism and immunoreactivity to S-100, anti-melanoma antibody (HMB-45) and melanocyte/melanoma tumor antigen (Melan-A). The diagnosis of primary small intestinal melanoma was confirmed. The patient underwent an uneventful postoperative recovery and was administered adjuvant therapy. At the 3-month, 6-month and 1-year follow-up, the patient remained alive, with no signs of tumor metastasis and/or recurrence. In this case, the patient was repetitively assessed by abdominal computed tomography (CT) and plain film, confirming that the obstruction was caused by small intestinal melanoma. There was no association between the rectal cancer history and the melanoma. A definitive diagnosis requires detailed clinical, histopathological and immunohistochemical analyses.

Preventing surgery-induced NK cell dysfunction and cancer metastases with influenza vaccination

Surgical resection is the mainstay of treatment for solid tumors, but the postoperative period is uniquely inclined to the formation of metastases, largely due to the suppression of natural killer (NK) cells. We found that preoperative influenza vaccination prevents postoperative NK-cell dysfunction, attenuating tumor dissemination in murine models and promoting the activation of NK cells in cancer patients.

[Metastasectomy in renal cell cancer after neoadjuvant therapy with multi-tyrosine kinase inhibitors]

BACKGROUND

Metastatic renal cell carcinoma (mRCC) still poses a challenge to therapists in spite of the availability of multiple innovative molecular treatment options. Complete remission is rare and in cases of partial remission it is often unclear if necrosis or vital carcinoma tissue persists. We report on a cohort of patients who underwent metastasectomy after neoadjuvant therapy with multi-tyrosine kinase inhibitors (MTKI).

METHODS

In 2009 a total of 11 patients (7 male and 4 female) underwent metastasectomy after achievement of ≥ 3 months stable partial remission. All patients received either sunitinib (n=7, mean 5.5 cycles), bevacizumab and interferon (IFN)-α2a (n=2, mean 8.5 months), temsirolimus (n=1, mean 9 months) or a combination of sunitinib followed by temsirolimus (n=1). Of the patients 7 presented with retroperitoneal lymph node metastases with a mean diameter of 3.5-12 cm, 2 patients with pulmonary metastases, 1 patient with lymph node and pancreas tail metastases and 1 female patient showed residual disease in the vena cava.

RESULTS

All metastases were completely resected with negative surgical margins. In 82% of the cases histologically active, Ki-67 positive renal cell cancer tissue was identified. The following adjunctive interventions were necessary: vena cava resection with vascular prosthesis and reimplantation of the renal vein (n=3), partial liver resection (n=1), splenectomy (n=1) and pancreas tail resection (n=1). There were no significant perioperative complications but 1 patient developed fascial dehiscence and underwent revision surgery and 1 patient developed clinically insignificant pancreatitis. After a median follow-up of 12 months (range 8-19 months) 5 patients had no recurrence and 6 of the patients showed liver (n=3), lung (n=2) or bone (n=1) recurrences from which 3 patients died.

CONCLUSIONS

Metastasectomy of mRCC is associated with a low rate of complications in experienced centers. Surgical resection of metastatic disease is indicated to achieve complete remission with a favorable prognosis because of biologically active kidney cancer tissue. Patients with isolated and resectable metastases are ideal candidates for such a procedure.

[Operative treatment of renal cell carcinoma]

Renal cell carcinoma represents the fifth most frequent malignant tumor in humans. At the time of diagnosis, 20% of the patients already manifest metastases. A further 20-30% of the patients develop systemic metastases in the postoperative course. Despite continued advances in pharmacological treatment options, cancer surgery tailored to the individual tumor findings constitutes the only curative treatment option.