Spontaneous regression of malignant tumors: Importance of the immune system and other factors (Review)

Spontaneous regression of advanced hepatocellular carcinoma following COVID-19 infection and vaccination: a case report and review of literature

Background

Spontaneous regression (SR) of cancer remains a rare phenomenon, particularly in hepatocellular carcinoma (HCC), where limited literature exists. This case report emphasizes the significance of SR in advanced HCC, shedding light on the proposed mechanisms and addressing the scarcity of documented cases in current medical literature.

Case Description

We present the case of a 67-year-old female with a history of localized HCC who underwent right hepatectomy. Surveillance imaging 4 months later revealed tumor recurrence with tumor thrombus in the main portal vein. Radioembolization was deemed unsuitable, leading to the recommendation of systemic therapy with atezolizumab and bevacizumab. Prior to receiving any treatment, the patient tested positive for coronavirus disease 2019 (COVID-19), having previously received both the messenger RNA (mRNA)-1273 vaccine series and a booster. Surprisingly, subsequent imaging 10 months after initial diagnosis showed SR of the previously identified lesions, suggesting a potential link between viral exposure, vaccination, and the observed regression. The patient eventually received treatment with atezolizumab and bevacizumab and has sustained disease control to date, 12 months after initiating treatment.

Conclusions

This unique case highlights SR of advanced HCC following COVID-19 infection, raising intriguing questions about the interplay between viral infections, vaccinations, and cancer outcomes. The patient's response in the absence of systemic therapy further underscores the complexity of HCC management and prompts further investigation into the potential immunomodulatory effects of viral infections and vaccinations on cancer regression. Understanding these interactions could have implications for tailoring treatment approaches and improving outcomes in patients with advanced HCC.

Comparative Study of Paraneoplastic and Nonparaneoplastic Autoimmune Encephalitis With GABABR Antibodies

BACKGROUND AND OBJECTIVES

While patients with paraneoplastic autoimmune encephalitis (AE) with gamma-aminobutyric-acid B receptor antibodies (GABABR-AE) have poor functional outcomes and high mortality, the prognosis of nonparaneoplastic cases has not been well studied.

METHODS

Patients with GABABR-AE from the French and the Dutch Paraneoplastic Neurologic Syndromes Reference Centers databases were retrospectively included and their data collected; the neurologic outcomes of paraneoplastic and nonparaneoplastic cases were compared. Immunoglobulin G (IgG) isotyping and human leukocyte antigen (HLA) genotyping were performed in patients with available samples.

RESULTS

A total of 111 patients (44/111 [40%] women) were enrolled, including 84 of 111 (76%) paraneoplastic and 18 of 111 (16%) nonparaneoplastic cases (cancer status was undetermined for 9 patients). Patients presented with seizures (88/111 [79%]), cognitive impairment (54/111 [49%]), and/or behavioral disorders (34/111 [31%]), and 54 of 111 (50%) were admitted in intensive care unit (ICU). Nonparaneoplastic patients were significantly younger (median age 54 years [range 19-88] vs 67 years [range 50-85] for paraneoplastic cases, p < 0.001) and showed a different demographic distribution. Nonparaneoplastic patients more often had CSF pleocytosis (17/17 [100%] vs 58/78 [74%], p = 0.02), were almost never associated with KTCD16-abs (1/16 [6%] vs 61/70 [87%], p < 0.001), and were more frequently treated with second-line immunotherapy (11/18 [61%] vs 18/82 [22%], p = 0.003). However, no difference of IgG subclass or HLA association was observed, although sample size was small (10 and 26 patients, respectively). After treatment, neurologic outcome was favorable (mRS ≤2) for 13 of 16 (81%) nonparaneoplastic and 37 of 84 (48%) paraneoplastic cases (p = 0.03), while 3 of 18 (17%) and 42 of 83 (51%) patients had died at last follow-up (p = 0.008), respectively. Neurologic outcome no longer differed after adjustment for confounding factors but seemed to be negatively associated with increased age and ICU admission. A better survival was associated with nonparaneoplastic cases, a younger age, and the use of immunosuppressive drugs.

DISCUSSION

Nonparaneoplastic GABABR-AE involved younger patients without associated KCTD16-abs and carried better neurologic and vital prognoses than paraneoplastic GABABR-AE, which might be due to a more intensive treatment strategy. A better understanding of immunologic mechanisms underlying both forms is needed.

Predicting disability and mortality in CV2/CRMP5-IgG associated paraneoplastic neurologic disorders

BACKGROUND

We aimed to investigate the prognostic factors associated with clinical outcomes in CV2/Collapsin response-mediator protein 5 (CRMP5)-IgG paraneoplastic neurologic disorders (PND).

METHODS

This is a retrospective study of patients with CV2/CRMP5-IgG PND evaluated between 2002-2022. We examined the association of clinical variables (including age, clinical phenotype [autoimmune encephalopathy, myelopathy, polyneuropathy/radiculopathy, MG, cerebellar ataxia, chorea, optic neuropathy], cancer) with three clinical outcomes (wheelchair dependence, modified Rankin Scale [mRS], mortality) using univariate logistic regression and Cox proportional hazards modeling. Kaplan-Meier estimates were used to determine the probability of survival.

RESULTS

Twenty-seven patients (56% female) with CV2/CRMP5-IgG PND were identified with a median follow-up of 54 months (IQR = 11-102). An underlying tumor was identified in 15 patients (56%) including small cell lung cancer (SCLC) (8, [53%]), thymoma (4, [27%]), and other histologies (3, [20%]). At last follow-up, 10 patients (37%) needed a wheelchair for mobility and this outcome was associated with myelopathy (HR = 7.57, 95% CI = 1.87-30.64, P = 0.005). Moderate-severe mRS = 3-5 was associated with CNS involvement (encephalopathy, myelopathy, or cerebellar ataxia) (OR = 7.00, 95% CI = 1.18-41.36, P = 0.032). The probability of survival 4 years after symptom onset was 66%. Among cancer subtypes, SCLC (HR = 18.18, 95% CI = 3.55-93.04, P < 0.001) was significantly associated with mortality, while thymoma was not.

INTERPRETATION

In this retrospective longitudinal study of CV2/CRMP5-IgG PND, patients with CNS involvement, particularly myelopathy, had higher probability of disability. SCLC was the main determinant of survival in this population.

Spontaneous Regression of Primary Cutaneous Diffuse Large B-Cell Lymphoma on Sequential FDG PET

ABSTRACT

Primary cutaneous diffuse large B-cell lymphoma, leg type is a rare, aggressive lymphoma characterized by skin involvement predominantly in the lower extremities. We present a case of an elderly woman with pathology diagnosis of primary cutaneous diffuse large B-cell lymphoma, leg type with spontaneous regression without systematic therapy documented by sequential FDG PET scans and clinical follow-up.

Role of Surgery in Metastatic Renal Cell Carcinoma

Surgery has historically been the mainstay of treatment for metastatic renal cell carcinoma (mRCC), but recent clinical trials demonstrated that contemporary systemic therapies alone are non-inferior to cytoreductive nephrectomy (CN). Thus, the current role of surgery is not precisely defined. CN remains an appropriate upfront treatment for the palliation of severe symptoms, select cases of metastatic non-clear cell renal cell carcinoma, for consolidation following systemic therapy, and in the setting of oligometastatic disease. Metastasectomy is ideally utilized to achieve a disease-free state when there is minimal morbidity associated with surgery. Given the heterogenous nature of mRCC, the decision for systemic therapy and surgery should be made through a multidisciplinary approach tailored to each individual patient.

Advanced in vitro models for renal cell carcinoma therapy design

Renal cell carcinoma (RCC) and its principal subtype, clear cell RCC, are the most diagnosed kidney cancer. Despite substantial improvement over the last decades, current pharmacological intervention still fails to achieve long-term therapeutic success. RCC is characterized by a high intra- and inter-tumoral heterogeneity and is heavily influenced by the crosstalk of the cells composing the tumor microenvironment, such as cancer-associated fibroblasts, endothelial cells and immune cells. Moreover, multiple physicochemical properties such as pH, interstitial pressure or oxygenation may also play an important role. These elements are often poorly recapitulated in in vitro models used for drug development. This inadequate recapitulation of the tumor is partially responsible for the current lack of an effective and curative treatment. Therefore, there are needs for more complex in vitro or ex vivo drug screening models. In this review, we discuss the current state-of-the-art of RCC models and suggest strategies for their further development.

What Can Trigger Spontaneous Regression of Breast Cancer?

BACKGROUND

Spontaneous regression of tumors is a rare phenomenon in which cancer volume is reduced or, alternatively, a tumor completely disappears in the absence of any pharmacological treatment. This phenomenon has previously been described in several tumors, such as neuroblastomas, testicular malignancies, renal cell carcinomas, melanomas, and lymphomas. Spontaneous remission has also been documented in breast cancer; however, it represents an extremely rare and poorly understood phenomenon, with only a few reported cases in the literature.

METHODS

We herein report two cases of breast cancer that showed spontaneous tumor regression in the surgical specimen after a pathologically confirmed diagnosis of invasive breast cancer in core needle biopsy samples.

RESULTS

Macroscopically, both the surgical samples revealed a whitish, fibrous area with a rubbery consistency. On histological examination, diffuse fibrous tissue, hemosiderin deposition, and chronic inflammation were observed. The first case showed the complete disappearance of the tumor, whereas the second case showed just a small (3 mm), residual nest of neoplastic cells.

CONCLUSIONS

Although spontaneous regression of breast cancer is a rare event, it is important to know that it might happen. It is also of great importance to try to better explain, over time, its underlying mechanism. This knowledge could help us to further develop cancer prevention methods and predict the clinical course of these kinds of neoplasms.

The Spontaneous Regression of Primary Gastrointestinal Malignancies: An Observational Review

The spontaneous regression or remission (SR) of cancer, often described as the partial or complete disappearance of a malignant tumor in the absence of all medical treatment and therapy, is a well-documented phenomenon. With efforts ongoing to establish cancer treatments that limit undesirable outcomes and adverse effects, these uncommon occurrences of SR carry significant implications for novel therapies and warrant further investigation. While several case studies have reported instances of SR in gastrointestinal (GI) malignancies, a comprehensive review of previous manifestations of SR in the GI tract remains lacking. The inclusion criteria for the rare phenomenon are also in need of an appropriate update that takes recent scientific advancements and emerging new medical technologies into account. Our analysis of 390 cases of SR in the GI tract focuses primarily on neoplasms of the hepatobiliary system and proposes an updated version of the older inclusion criteria for spontaneous regression.

Apoptotic and mitotic indices in oral epithelial dysplasia and squamous cell carcinoma: A comparative study

Background

Assessment of apoptotic cells and mitotic figures using light microscopy is an easy and viable alternative to assess tumour behaviour.

Aims

To evaluate apoptotic index (AI), mitotic index (MI) and apoptotic to mitotic index ratio (AI: MI) in different grades of oral epithelial dysplasia (OED) and oral squamous cell carcinoma (OSCC) in haematoxylin and eosin-stained (H&E) sections.

Settings and Design

The study included 45 cases each of OED and OSCC cases which were further subgrouped into groups of 15 each based on their grades. AI, MI and AI/MI were assessed and compared with 15 cases of normal mucosa.

Methods and Material

Apoptotic cells and mitotic figures were counted using a binocular light microscope equipped with an oculometer grid (20 × 20 squares) on the eyepiece. Cells were counted in 15 grid fields under oil immersion lenses (×100) in a stepladder fashion. AI/MI ratio was calculated.

Statistical Analysis

The results obtained were statistically analysed using Analysis of variance and Tukey Honestly Significant Difference tests with SPSS 20 software at a 0.05 significance level.

Results

AI increased with increasing grades of dysplasia and decreased with increasing grades of OSCC. MI increased with increasing grades of OED and OSCC. AI/MI increased with increasing grades of OED but decreased with increasing grades of OSCC.

Conclusion

In the light of the current observations, AI, MI and AI: MI can be considered as valuable parameters to assess the biological behaviour of OED and OSCC.

Congenital solitary reticulohistiocytosis (Hashimoto - Pritzker) - Case report

Congenital and self-healing Hashimoto-Pritzker reticulohistiocytosis is the benign variant of the Langerhans cell histiocytosis (LCH) group. It is characterized by multiple skin lesions (congenital or appearing during the first days after birth), without systemic manifestations and spontaneous resolution in days to months. The authors report the case of a boy with a single congenital leg skin lesion, a rare disease variant. Through histopathology, a dense skin infiltration of S100 protein-, CD1a-, CD207-immunomarked cells was found. KI67 index was high (62%). A complete spontaneous resolution occurred 07 days after the biopsy (25 days after birth). Monolesional disease, distal limb lesion, absence of lesions in the mucous membrane or seborrheic area, and less than 25 percent of LCs with Birbeck granules were said to be possible clues for a favorable prognosis in LCs histiocytosis. But, as a precautionary measure, the child will be followed up until at least 2 years of age.

Spontaneous regression of a posterior fossa meningioma: A case report

Background:

Since most incidentally discovered meningiomas grow or remain unchanged, spontaneous regression is extremely rare. Here, we report a case of posterior fossa meningioma showing spontaneous regression.

Case Description:

A 55-year-old female was referred to our hospital because she was diagnosed with a left posterior fossa meningioma (diameter: 1.6 cm) during a brain check-up. The patient was followed up on periodic magnetic resonance imaging studies. Tumor size remained almost unchanged for 2 years but then began to regress. Twelve years after the initial examination, the tumor diameter idiopathically decreased from 1.6 cm to 1.1 cm while the tumor volume decreased from 2.3 cm³ to 0.5 cm³ (about 1/4^th the original size). Postmenopausal hormonal imbalances may have been associated with the observed spontaneous regression.

Conclusion:

Understanding the natural history of meningiomas is essential for a better selection of treatment approaches or appropriate follow-up. This case may provide new insights into the progression of meningiomas.

Spontaneous Regression of Metastatic Lesions of Adenocarcinoma of the Gastro-Esophageal Junction

Spontaneous regression of cancer is a rarely recognized entity in modern medicine. Historically, this was recognized and hypothesized that an infection causes immune activation, indirectly stimulating the body to destroy tumor cells. Similarly, immune-oncology has now become a major modality in the treatment of solid and some liquid malignancies. However, now with improved therapeutic modalities in the oncology world, one does not get to appreciate our own immune system's ability to fight cancer. We present a patient who had spontaneous regression of metastatic adenocarcinoma of the gastroesophageal junction (GEJ). The patient is a 58-year-old female who had presented with early satiety and dysphagia for which she underwent esophagogastroduodenoscopy which showed an esophageal mass and endoscopic ultrasounds (EUSs) confirmed adenocarcinoma of the GEJ with metastasis to the regional lymph nodes and left supraclavicular lymph nodes. The patient had refused to undergo any surgical, medical oncological, or holistic treatments. Interim disease monitoring positron emission tomography-computed tomography (PET-CT) showed resolution of the metastatic sites of gastroesophageal cancer with clinical improvement of her symptoms. She continues to have this distant regression of metastatic gastroesophageal cancer six months after the initial diagnosis. In literature, spontaneous cancer regression has been reported in melanoma, renal cell carcinoma, and basal cell carcinoma. To our knowledge, this is the first case reported of spontaneous regression of metastatic lesions involving adenocarcinoma of the GEJ with no medical or surgical intervention.

Pancreatic enzyme autodigestion of an unresectable retroperitoneal liposarcoma

This is a case of a 71-year-old man who had multiple synchronous retroperitoneal liposarcoma (LPS) foci composed of both well-differentiated and dedifferentiated histologies. In addressing this, the patient underwent a margin negative resection of a 11.8×8.8 cm right-sided dedifferentiated LPS requiring pancreaticoduodenectomy; however, a 13.1×7.2 cm left-sided well-differentiated LPS (WDLPS) was not resected due to its involvement of the proximal mesenteric vessels. The patient's postoperative course was complicated by grade B postoperative pancreatic fistula involving the anatomical territory of the residual WDLPS. Over the next 12 months, serial CT scans demonstrated a stepwise reduction in size of the WDLPS until it completely regressed. The authors hypothesise that enzymes shed from the pancreatic fistula initiated the autodigestion and subsequent necrosis of the WDLPS with associated tumour regression.

The spontaneous remission of cancer: Current insights and therapeutic significance

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Spontaneous remission (SR) of cancer is a rare but well-documented phenomenon.

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Mechanisms of SR are described in detail.

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Knowing the intricacies of SR would help in devising novel treatment strategies.

Many diseases heal spontaneously. The common cold, for example, remedies itself within a few days in people with an uncompromised immune system. If a disease with a poor prognosis heals in the absence of a targeted therapeutic, many even call it a miracle cure. Such is the case with the spontaneous regression (SR) of malignant neoplasms, a rare but well-documented phenomenon that finds its first mention in the Ebers Papyrus of 1550 BCE. Given the challenges associated with current cancer treatment modalities such as rapidly evolving drug resistance mechanisms, dose-limiting side effects, and a failure to completely eliminate cancer cells, knowledge of how a tumour heals itself would be immensely helpful in developing more effective therapeutic modalities. Although the intricate mechanisms of SR have yet to be fully elucidated, it has been shown that infection-mediated immune system activation, biopsy procedures, and disruptions of the tumour microenvironment play pivotal roles in the self-healing of many tumours. Bacterial and viral infections are especially well-documented in instances of SR. Insights from these findings are paving the way for novel therapeutic strategies. Inspired by bacteria-mediated SR, Bacillus Calmette-Guérin (BCG) has been used as an approved treatment option for non-muscle-invasive bladder cancer (NMIBC). Similarly, Talimogene laherparepvec (T-VEC), the first engineered oncolytic herpes simplex virus (HSV), has been approved by the United States Food and Drug Administration for the treatment of some forms of advanced melanoma. Here we describe the current understanding of SR, explore its therapeutic significance, and offer perspectives on its future.

Spontaneous regression of multiple pulmonary metastases accompanied by normalization of serum immune markers following cytoreductive nephrectomy in a patient with clear-cell renal cell carcinoma

INTRODUCTION

The spontaneous regression of metastases, which mostly occurs after surgical resection of the primary tumor, has been described in various malignancies, including renal cell carcinoma. The involvement of the host immune system is currently postulated as the underlying mechanism.

CASE PRESENTATION

We present a case of metastatic clear-cell renal cell carcinoma that achieved complete spontaneous regression of multiple pulmonary metastases preceded by normalization of serum immune markers after cytoreductive nephrectomy. The patient remained disease free for 3 years without any systemic therapy, suggesting that postoperative normalization of serum immune markers may indicate recovery of the host immune system, which prevents tumor recurrence.

CONCLUSION

Monitoring of serum immune markers may be useful to identify patients with recovered immune function and, therefore, may not require systemic therapy. Similarly, the case suggests a potential role of cytoreductive nephrectomy in the contemporary management of metastatic renal cell carcinoma.

A Secretory Variant of Cerebral Meningioma with Partial Spontaneous Regression in a Cow

A 3.5-year-old Holstein cow presented with a 2-week history of weakness, ataxia and difficulty in rising, followed by recumbency. At necropsy, a 3 × 2.5 cm tumour mass was found in the subdural area of the left parietal lobe of the cerebrum. Histopathology revealed the tumour to be a variant of secretory meningeal tumour. Immunohistochemically, all of the neoplastic cells expressed vimentin and some were immunopositive for cytokeratin. There were variably sized, scattered pseudocysts containing eosinophilic material that stained positively with Alcian blue and periodic acid-Schiff stains. The marginal zone of the tumour exhibited regressive change characterized by lymphocytic infiltration and extensive fibrotic areas enclosing large numbers of tumour cell nests in which most tumour cells were apoptotic. This tumour was considered to be a secretory variant of cerebral meningioma with partial spontaneous regression.

Spontaneous regression of ALK fusion protein-positive non-small cell lung carcinoma: a case report and review of the literature

BACKGROUND

ALK-rearrangement is observed in < 5% non-small cell lung cancer (NSCLC) cases and prior to the advent of oral tyrosine kinase inhibitors, the natural history of oncogenic NSCLC was typically poor. Literature relating to regression of treatment-naïve NSCLC is limited, and regression without treatment has not been noted in the ALK-rearranged sub-population.

CASE PRESENTATION

A 76 year old 'never smoker' female with an ALK-rearranged left upper lobe T2 N0 NSCLC experienced a stroke following elective DC cardioversion for new atrial fibrillation. Following a good recovery, updated imaging demonstrated complete regression of the left upper lobe lesion and a reduction of the previously documented mediastinal lymph node. Remaining atelectasis was non-avid on repeat PET-CT imaging, 8 months from the baseline PET-CT. When the patient developed new symptoms 6 months later a further PET-CT demonstrated FDG-avid local recurrence. She completed 55 Gy in 20 fractions but at 18 months post-radiotherapy there was radiological progression in the lungs with new pulmonary metastases and effusion and new bone metastases. Owing to poor performance status, she was not considered fit for targeted therapy and died 5 months later.

CONCLUSION

All reported cases of spontaneous regression in lung cancer have been collated within. Documented precipitants of spontaneous regression across tumour types include biopsy and immune reconstitution; stroke has not been reported previously. The favourable response achieved with radical radiotherapy alone in this unusual case of indolent oncogenic NSCLC reinforces the applicability of radiotherapy in locally advanced ALK-rearranged tumours, in cases not behaving aggressively. As a common embolic event affecting the neurological and pulmonary vasculature is less likely, an immune-mediated mechanism may underpin the phenomenon described in this patient, implying that hitherto unharnessed principles of immuno-oncology may have relevance in oncogenic NSCLC. Alternatively, high electrical voltage applied percutaneously adjacent to the tumour during cardioversion in this patient may have induced local tumour cell lethality.

Context-dependent HOX transcription factor function in health and disease

During animal development, HOX transcription factors determine the fate of developing tissues to generate diverse organs and appendages. The power of these proteins is striking: mis-expressing a HOX protein causes homeotic transformation of one body part into another. During development, HOX proteins interpret their cellular context through protein interactions, alternative splicing, and post-translational modifications to regulate cell proliferation, cell death, cell migration, cell differentiation, and angiogenesis. Although mutation and/or mis-expression of HOX proteins during development can be lethal, changes in HOX proteins that do not pattern vital organs can result in survivable malformations. In adults, mutation and/or mis-expression of HOX proteins disrupts their gene regulatory networks, deregulating cell behaviors and leading to arthritis and cancer. On the molecular level, HOX proteins are composed of DNA binding homeodomain, and large regions of unstructured, or intrinsically disordered, protein sequence. The primary roles of HOX proteins in arthritis and cancer suggest that mutations associated with these diseases in both the structured and disordered regions of HOX proteins can have substantial functional effects. These insights lead to new questions critical for understanding and manipulating HOX function in physiological and pathological conditions.

Single-Cell Proteomic Profiling Identifies Combined AXL and JAK1 Inhibition as a Novel Therapeutic Strategy for Lung Cancer

Cytometry by time-of-flight (CyTOF) simultaneously measures multiple cellular proteins at the single-cell level and is used to assess intertumor and intratumor heterogeneity. This approach may be used to investigate the variability of individual tumor responses to treatments. Herein, we stratified lung tumor subpopulations based on AXL signaling as a potential targeting strategy. Integrative transcriptome analyses were used to investigate how TP-0903, an AXL kinase inhibitor, influences redundant oncogenic pathways in metastatic lung cancer cells. CyTOF profiling revealed that AXL inhibition suppressed SMAD4/TGFβ signaling and induced JAK1-STAT3 signaling to compensate for the loss of AXL. Interestingly, high JAK1-STAT3 was associated with increased levels of AXL in treatment-naïve tumors. Tumors with high AXL, TGFβ, and JAK1 signaling concomitantly displayed CD133-mediated cancer stemness and hybrid epithelial-to-mesenchymal transition features in advanced-stage patients, suggesting greater potential for distant dissemination. Diffusion pseudotime analysis revealed cell-fate trajectories among four different categories that were linked to clinicopathologic features for each patient. Patient-derived organoids (PDO) obtained from tumors with high AXL and JAK1 were sensitive to TP-0903 and ruxolitinib (JAK inhibitor) treatments, supporting the CyTOF findings. This study shows that single-cell proteomic profiling of treatment-naïve lung tumors, coupled with ex vivo testing of PDOs, identifies continuous AXL, TGFβ, and JAK1-STAT3 signal activation in select tumors that may be targeted by combined AXL-JAK1 inhibition. SIGNIFICANCE: Single-cell proteomic profiling of clinical samples may facilitate the optimal selection of novel drug targets, interpretation of early-phase clinical trial data, and development of predictive biomarkers valuable for patient stratification.

Metastatic Anaplastic Thyroid Carcinoma in Complete Remission: Morphological, Molecular, and Clinical Work-Up of a Rare Case

Anaplastic thyroid carcinoma (ATC) exhibits an exceedingly poor prognosis, and the current treatment options are, for most cases, palliative by nature. Few reports of long-time survivors exist, although in these patients, tumors often were limited to the thyroid and/or regional lymph nodes. We describe a 64-year-old male who developed a rapidly growing mass in the left thyroid lobe. A fine-needle aspiration biopsy (FNAB) was consistent with ATC, and the patient underwent preoperative combined chemo- and radiotherapy followed by a hemithyroidectomy. The ensuing histopathological investigation was consistent with ATC adjoined by an oxyphilic well-differentiated lesion, likely a Hürthle cell carcinoma. Tumor margins were negative, and no extrathyroidal extension was noted. Focused next-generation sequencing analysis of the primary tumor tissue identified a TP53 gene mutation but could not identify any potential druggable targets. Additional Sanger sequencing detected a C228T TERT promoter mutation. The tumor was found to be microsatellite stable and displayed PDL1 expression in 80% of tumor cells. Following a CT scan 1 month postoperatively, metastatic deposits were suspected in the lung as well as in the left adrenal gland, of which FNAB verified the latter. Remarkably, upon radiological follow-up, the disease had gone into apparent complete remission. The patient is alive and well with no signs of residual disease after 12 months of follow-up. We here summarize the clinical, histological, and molecular data of this highly interesting patient case and review the literature for possible common denominators with other patients with disseminated ATC.

Spontaneous regression of occult breast cancer with axillary lymph node metastasis: A case report

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This case showed spontaneous regression of both the primary and metastasis lesions.

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Histopathological findings suggested spontaneous regression of the tumor.

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The presence of CD8-positive lymphocytes suggests involvement of the immune response.

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Poor prognostic factors of malignant tumors might induce spontaneous regression.

Introduction

Spontaneous regression of a malignant tumor is defined as “the partial or complete disappearance of a malignant tumor in the absence of any treatment.” Herein, we report a case of occult breast cancer with axillary lymph node metastasis that showed spontaneous tumor regression based on the histopathological findings.

Presentation of the case

A 67-year-old woman presented with left armpit pain and a lump. Previous examination by another doctor revealed swelling of the left axillary lymph node, but it was difficult to identify the primary lesion. Needle biopsy of the left axillary lymph node revealed malignant tumor tissue with extensive necrosis on histological examination. On initial examination at our hospital, the left axillary lymph node was observed to have shrunk compared to previous observations. Moreover, findings indicated a suspected concentrated cyst in the left breast, with slight contrast enhancement on magnetic resonance imaging. Considering a diagnosis of occult breast cancer with axillary lymph node metastasis, excisional biopsy was performed for the left breast mass and axillary lymph node dissection for left axillary lymph node metastasis. Histological examination revealed a micro adenocarcinoma with lymphocyte infiltration in the left breast, and the viable tumor in the left axillary lymph node had disappeared. The histopathological findings of the primary tumor and dissected lymph nodes suggested the possibility of spontaneous regression of both the primary and metastatic lesions, because effective preoperative therapy was not performed.

A Case of Spontaneous Regression of Pulmonary Small Cell Carcinoma

An 82-year-old man was examined using chest computed tomography after treatment for pneumonia. Imaging showed a nodular shadow in the left lower lobe with associated enlarged lymph nodes. A polypoid tumour was observed on bronchoscopic examination, and the histological findings showed pulmonary small cell carcinoma with infiltration of CD3-positive and CD8-positive lymphocytes. The patient declined any antitumoural therapy and experienced an exacerbation of heart failure treated with atrial natriuretic peptide. Eighteen months after the diagnosis, the polypoid tumour had disappeared. T lymphocyte-mediated immunity and the antitumoural effects of atrial natriuretic peptide may have influenced the observed spontaneous regression.

Relationship between haematological profile and progression or spontaneous regression of melanoma in the Melanoma-bearing Libechov Minipigs

Haematological parameters, plasma iron concentration, and bodyweight were monitored in Melanoma-bearing Libechov Minipigs (MeLiM) from 5 to 18 weeks old. Animals with melanoma progression (P group) and spontaneous regression (SR group) were compared. The P group showed the lowest median values of red blood cell counts (RBC), haematocrit (HCT), haemoglobin concentration (HGB), and bodyweight, whereas the control white (tumour-free) pigs (C group) revealed the highest mean values of these parameters. The mean values of pigs with SR fell between the P and C groups. In addition, a stable concentration of plasma iron was found in the C group, while iron deficiency that increases with age was observed in the MeLiM groups. These results indicate that MeLiM are affected by cancer-related microcytic hypochromic anaemia. The lowest values of HGB, RBC, and HCT, together with the highest number of platelets (PLT) in the P group correspond to melanoma progression. Higher values of these parameters and lower PLT in the MeLiM pigs with SR reflected health improvement due to the destruction of melanoma cells during spontaneous regression. Monitoring of these haematological parameters can help distinguish MeLiM piglets with progression and spontaneous regression of melanoma in the early stages of postnatal development. The findings of this study correspond to findings in human patients in which cancer-related anaemia, thrombocytosis, and iron deficiency are often diagnosed.

Spontaneous regression of diffuse large B-cell lymphoma in the small intestine with multiple lymphadenopathy

Diffuse large B cell lymphoma (DLBCL) is classified as an aggressive lymphoma due to its poor prognosis regardless of the treatment. Almost all cases of DLBCL are treated using rituximab-combination chemotherapy, but spontaneous regression without any therapeutic modalities may rarely occur. A 35-year-old man complained of abdominal pain and discomfort. Positron emission tomography-computed tomography (PET-CT) demonstrated abnormal accumulation of fluorodeoxyglucose in the thickened wall of the small intestine and multiple lymphadenopathy. Laparoscopic lymph node biopsy was performed, and the diagnosis of DLBCL was made based on the biopsy findings. Soon after the laparoscopic biopsy, the patient felt free from any symptoms. Approximately three months later, no abnormal accumulation of fluorodeoxyglucose in the entire body was found on PET-CT. He has remained in complete metabolic remission for over three years according to PET-CT. We discuss the mechanism of this rare phenomenon.

Immunohistochemical Evidence of the Involvement of Natural Killer (CD161+) Cells in Spontaneous Regression of Lewis Rat Sarcoma

BACKGROUND/AIM

Spontaneous regression (SR) of tumours is a rare phenomenon not yet fully understood. The aim of this study was to investigate immune cells infiltrating progressive and SR tumours in a Lewis rat sarcoma model.

MATERIALS AND METHODS

Rats were subcutaneously inoculated with rat sarcoma R5-28 (clone C4) cells. Developing tumours were obtained on day 42 and cryosections were immunohistochemically processed for detection of immune cells.

RESULTS

A high density of granulocytes was found in the necrotic areas of both progressive and SR tumours. CD4⁺ cells and CD8⁺ cells were rare and sparsely dispersed in the tumour tissue without clear difference between the two types of tumours. On the contrary, CD161⁺ cells were abundant and evenly distributed in SR tumours, but these cells were very rare in progressive tumours.

CONCLUSION

Based on the differences in number and distribution of the immune cell subpopulations, we believe that natural killer (CD161⁺) cells play a major role in the destruction of cancer cells during SR of tumours in this Lewis rat model.

Primary Cutaneous Diffuse Large B-Cell Lymphoma, Leg Type, With Spontaneous Regression After Biopsy

Primary cutaneous diffuse large B-cell lymphoma, leg type (PCDLBCL-LT) represents approximately 20% of cutaneous B lymphomas with an intermediate prognosis. Spontaneous regression is uncommon; there are only 2 published cases. An 83-year-old woman presented 2 orange erythematous nodules on the back of her right leg with an elastic consistency, infiltrated, painful to the touch, and of an 8-month evolution. A histological examination revealed a dense cellular dermo-hypodermic infiltrate sparing the papillary dermis, composed of large cells with immunoblast and centroblast morphology and frequent mitosis. Immunohistochemical studies showed positivity for CD20, CD79, Bcl2, Bcl6, MUM1, Fox-P1, and IgM with Ki67 >95%. Rearrangement of heavy IgH chains was monoclonal. The extension study was negative, establishing a diagnosis of PCDLBCL-LT, T2aN0M0. Three months after biopsy, the patient's lesions regressed spontaneously. New biopsies were taken that revealed a mild diffused dermo-hypodermic cellular infiltrate compounded by small-sized T lymphocytes, with predominance of CD8. Despite its self-limited character, treatment with radiotherapy was done, remaining asymptomatic after 1 year follow-up. There are 2 published cases of PCDLBCL-LT with spontaneous regression. The cause of this unusual autoinvolutional phenomenon is unknown; it may be an immune response against tumor cells through a traumatic or infectious mechanism.

MATHEMATICAL MODELING OF THE INTERPLAY BETWEEN STRESS AND ANISOTROPIC GROWTH OF AVASCULAR TUMORS

In this work, we propose a new mathematical framework for the study of the mutual interplay between anisotropic growth and stresses of an avascular tumor surrounded by an external medium. The mechanical response of the tumor is dictated by anisotropic growth, and reduces to that of an elastic, isotropic, and incompressible material when the latter is not taking place. Both proliferation and death of tumor cells are in turn assumed to depend on the stresses. We perform a parametric analysis in terms of key parameters representing growth anisotropy and the influence of stresses on tumor growth in order to determine how these effects affect tumor progression. We observe that tumor progression is enhanced when anisotropic growth is considered, and that mechanical stresses play a major role in limiting tumor growth.

Spontaneous regression of pancreatic cancer: A case report and literature review

INTRODUCTION

Spontaneous regression of cancer is defined as the partial or complete disappearance of malignant disease without treatment, or in the presence of therapy that is deemed inadequate to exert an influence on malignant disease, as composed by Tilden Everson and Warren Cole in the 1960s. It has been a topic of major interest in the field of medical and surgical oncology. It is poorly understood and scantily documented. Factors associated and postulated pathogeneses are at best, hypothetical.

PRESENTATION OF CASE

We report a case of spontaneous resolution of a head of pancreas carcinoma in a 77-year-old gentleman after a myocardial infarction event delayed planned surgery.

DISCUSSION

A literature review of previously reported cases of spontaneous regression of pancreatic cancer was performed. The possible predisposing factors to spontaneous regression of pancreatic and other forms of malignancies was reviewed.

CONCLUSION

This is a novel case of spontaneous regression of pancreatic carcinoma after an episode of myocardial infarction. The pathophysiology to spontaneous resolution of cancer is not well understood, may be multifactorial and requires further study.

Regression of Recurrent High-Grade Glioma with Temozolomide, Dexamethasone, and Levetiracetam: Case Report and Review of the Literature

BACKGROUND

Treatment options for recurrent glioma of the brain include chemotherapy, radiotherapy, surgery, and palliation. Temozolomide appears to be effective in patients with recurrent high-grade gliomas.

CASE DESCRIPTION

A middle-aged woman presented with a high-grade glioma of corpus callosum. The tumor, a grade 3 anaplastic oligodendroglioma, was excised, and chemoradiotherapy was administered. The patient presented with significant recurrence 5 years later. Repeat surgery and radiation were suggested but refused. She was given temozolomide and dexamethasone intermittently, and levetiracetam was continued. Magnetic resonance imaging performed at 10-month follow-up showed 90% remission.

CONCLUSIONS

There are a few reports in the literature of similar response to temozolomide and levetiracetam. Similar reports give more hope in the treatment of recurrent high grade glioma.

Spontaneous regression of gestational trophoblastic neoplasia

•We present two cases of postmolar gestational trophoblastic neoplasia (GTN).•Both cases presented with lung metastases after hydatidiform mole.•Both cases showed spontaneous regression without treatment.•The mechanism behind this phenomenon remains unclear.•Patients with postmolar GTN and declining hCG values may not need chemotherapy.

Clear Cell Renal Cell Carcinoma with Intratumoral Granulomatous Reaction: A Case Report and Review of the Literature

Granulomatous reaction associated with clear cell renal cell carcinoma (CCRCC) is a rare finding, and only a few cases have been described in the literature. It is postulated to occur due to cancer-related antigenic factors such as cancer cells themselves or soluble tumor antigens shed into the blood. Herein, we describe a case of a 56-year-old male patient diagnosed with CCRCC with intratumoral granulomatous inflammation.

Spontaneous Regression of Intravascular Large B-Cell Lymphoma and Apoptosis of Lymphoma Cells: A Case Report

A 61-year-old Japanese woman presented with hemophagocytic syndrome (HPS) and suffered from intravascular large B-cell lymphoma (IVLBCL). After a few days of supportive care, her condition improved without any anti-cancer drugs or steroids. She experienced recurrences of HPS at 15 mon and 21 mon after first presentation, but lymphoma cells were not observed. Relapse of IVLBCL with pulmonary involvement occurred 27 mon after first presentation. She underwent R-CHOP therapy followed by autologous stem cell transplantation. She is currently alive and without lymphoma. Immunostaining by anti-ssDNA suggested that spontaneous regression may have been due to apoptosis of the lymphoma cells.

A phase I study of intratumoral ipilimumab and interleukin-2 in patients with advanced melanoma

PURPOSE

Intratumoral interleukin-2 (IL-2) is effective but does not generate systemic immunity. Intravenous ipilimumab produces durable clinical response in a minority of patients, with potentially severe toxicities. Circulating anti-tumor T cells activated by ipilimumab may differ greatly from tumor-infiltrating lymphocytes activated by intratumoral ipilimumab in phenotypes and functionality. The objective of this study was to primarily assess the safety of intratumoral ipilimumab/IL-2 combination and to obtain data on clinical efficacy.

RESULTS

There was no dose limiting toxicity. While local response of injected lesions was observed in 67% patients (95% CI, 40%-93%), an abscopal response was seen in 89% (95% CI, 68%-100%). The overall response rate and clinical benefit rate by immune-related response criteria (irRC) was 40% (95% CI, 10%-70%) and 50% (95% CI, 19%-81%), respectively. Enhanced systemic immune response was observed in most patients and correlated with clinical responses.

EXPERIMENTAL DESIGN

Twelve patients with unresectable stages III/IV melanoma were enrolled. A standard 3+3 design was employed to assess highest tolerable intratumoral dose of ipilimumab and IL-2 based on toxicity during the first three weeks. Escalated doses of ipilimumab was injected into only one lesion weekly for eight weeks in cohorts of three patients. A fixed dose of IL-2 was injected three times a week into the same lesion for two weeks, followed by two times a week for six weeks.

CONCLUSIONS

Intratumoral injection with the combination of ipilimumab/IL-2 is well tolerated and generates responses in both injected and non-injected lesions in the majority of patients.

Spontaneous regression of multiple pulmonary nodules in a patient with unclassified renal cell carcinoma following laparoscopic partial nephrectomy: A case report

Spontaneous regression of metastatic renal cell carcinoma (RCC) is rare, but well-documented in clear cell RCC. However, there are no reports on spontaneous regression of unclassified RCC. Since the radiological findings of pulmonary infarcts and inflammatory pseudotumors are similar to those of metastases from RCC, a definitive diagnosis is difficult without performing a histological examination. A 56-year-old woman underwent medical examination by a physician. An abdominal computed tomography (CT) scan revealed a 22-mm mass with a cystic area in the right kidney, as well as multiple enlarged lymph nodes in the common iliac, external iliac and groin areas, bilaterally. A chest CT revealed multiple pulmonary nodules bilaterally, the largest measuring 15 mm. Since the right renal tumor was suspected to be an RCC, laparoscopic partial nephrectomy was performed. The final pathological diagnosis of the renal tumor was unclassified RCC. One month following surgery, a CT scan revealed spontaneous regression of the pulmonary nodules. We herein present a rare case of spontaneous regression of pulmonary nodules in a patient with unclassified RCC following laparoscopic partial nephrectomy. To the best of our knowledge, this is the first case of spontaneous regression in unclassified RCC.

Spontaneous Regression of an Incidental Spinal Meningioma

AIM:

The regression of meningioma has been reported in literature before. In spite of the fact that the regression may be involved by hemorrhage, calcification or some drugs withdrawal, it is rarely observed spontaneously.

CASE REPORT:

We report a 17 year old man with a cervical meningioma which was incidentally detected. In his cervical MRI an extradural, cranio-caudal contrast enchanced lesion at C2-C3 levels of the cervical spinal cord was detected. Despite the slight compression towards the spinal cord, he had no symptoms and refused any kind of surgical approach. The meningioma was followed by control MRI and it spontaneously regressed within six months. There were no signs of hemorrhage or calcification.

CONCLUSION:

Although it is a rare condition, the clinicians should consider that meningiomas especially incidentally diagnosed may be regressed spontaneously.

Granulomatous inflammation of pulmonary squamous cell carcinoma: a rare phenomenon

Some neoplasms are associated with granulomatous inflammation. Granuloma formation in tumor tissue is caused by the cytokines derived from either the main tumor or other cells surrounding the tumor. In other instances, granulomatous inflammation is observed in the lymph nodes draining a tumor. This has been recognized as a sarcoid-like reaction. Herein, we report of a 75-year-old man with pulmonary squamous cell carcinoma (SCC), where granulomatous inflammation was observed extensively at the primary site. The carcinoma seemed to partly regress. In the regressing area, tumor cell debris was surrounded by granuloma. In contrast, no granuloma was identified in the dissected regional lymph nodes. To the best of our knowledge, such a case of SCC had not been described thus far. More case studies are required to determine whether tumor-related granuloma is the main cause of regression or whether it is just a secondary phenomenon caused by the attack and destruction of the tumor by lymphocytes.

The abscopal effect of local radiotherapy: using immunotherapy to make a rare event clinically relevant

BACKGROUND

Recently, immunologic responses to localized irradiation are proposed as mediator of systemic effects after localized radiotherapy (called the abscopal effect). Here, we give an overview of both preclinical and clinical data about the abscopal effect in particular and link them with the immunogenic properties of radiotherapy.

METHODS

We searched Medline and Embase with the search term "abscopal", "(non-targeted irradiation) OR (non-targeted radiotherapy)" and "distant bystander" from 1960 until July, 2014. Only papers that cover radiotherapy in an oncological setting were selected and only if no concurrent cytotoxic treatment was given. Targeted immune therapy was allowed.

RESULTS

Twenty-three case reports, one retrospective study and 13 preclinical papers were selected. Eleven preclinical papers used a combination of immune modification and radiotherapy to achieve abscopal effects. Patient age range (28-83years) and radiation dose (median total dose 32Gy) varied. Fractionation size ranged from 1.2Gy to 26Gy. Time to documented abscopal response ranged between less than one and 24months, with a median reported time of 5months. Once an abscopal response was achieved, a median time of 13months went by before disease progression occurred or the reported follow-up ended (range 3-39months).

CONCLUSION

Preclinical data points heavily toward a strong synergy between radiotherapy and immune treatments. Recent case reports already illustrate that such a systemic effect of radiotherapy is possible when enhanced by targeted immune treatments. However, several issues concerning dosage, timing, patient selection and toxicity need to be resolved before the abscopal effect can become clinically relevant.

Aggressive multimodal therapy may prolong disease-free survival in recurrent primary retroperitoneal embryonal carcinoma

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5% of extragonadal germ cell tumours are currently considered to be of primary retroperitoneal origin.

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Retroperitoneal EGGCTs are assumed to a poor prognosis group even if they fulfill the IGCCCG criteria for good, or intermediate prognosis.

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The combination of radical surgery and chemotherapy may prolong disease-free survival even in a second- or third-line treatment.

Introduction

Primary retroperitoneal extragonadal tumours relapsing after initial chemotherapy have a poor prognosis.

Presentation of the case

We report a case of primary retroperitoneal embryonal carcinoma in a patient with negative open testes biopsy. After the first line of chemotherapy (4 cycles BEP) secondary surgery with extirpation of a retroperitoneal residual mass was performed. The residuum proved histologically to be a mature teratoma, and no adjuvant treatment was given according to current recommendations. The patient had regular follow-up. 3.5 years later, patient developed recurrence in the ipsilateral adrenal gland, which was treated with surgery and 4 cycles of salvage VeIP chemotherapy. Seven months after the second surgical intervention the patient underwent multivisceral “desperation surgery” for early metastatic disease progression followed by 2 cycles of salvage TIP chemotherapy. The patient is currently disease-free at 34 months.

Conclusion

Initial postchemotherapy retroperitoneal lymph node dissection is crucial for local retroperitoneal disease control. Aggressively treated metastatic recurrent disease does not preclude prolonged survival. Despite a generally poor prognosis, repeated complex oncosurgical therapy for retroperitoneal extragonadal tumours may be worthwhile.

Spontaneous regression of primary extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) colliding with invasive ductal carcinoma of the breast: a case report

Malignant lymphomas of the breast, whether they are primary or secondary, are rare diseases, constituting only around 0.1 to 0.15% of the primary neoplasm of the breast. Although the most prevalent histological subtype is diffuse large B-cell lymphoma, primary extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) also occurs in the breast as in other extranodal sites, comprising about 15% of malignant lymphomas of the breast. In many cases, primary MALT lymphoma of the breast is low grade lymphoma, localized in the breast with indolent behavior and good prognosis. Here we report a case of spontaneous regression of primary MALT lymphoma of the breast. The lymphoma collided with invasive ductal carcinoma in the breast. Both tumors were identified in the Vacora biopsy specimen before the operation. However, the lymphoma disappeared, while the carcinoma remained, in the resected mass. To our knowledge, this is the first case report of spontaneous regression of MALT lymphoma of the breast colliding with breast cancer.

Spontaneous regression together with increased calcification of incidental meningioma

BACKGROUND

Regression of meningioma has been reported after hemorrhage or hormonal withdrawal. However, meningioma regression is rarely observed spontaneously.

CASE DESCRIPTION

A right falx meningioma was incidentally diagnosed and was followed at every one-year by magnetic resonance imaging (MRI) for over 7 years. The tumor, with a maximum diameter of 4 cm, showed a slightly high density and was enhanced on computed tomography (CT), and a high intensity with a low-intensity core on T2 MRI, with significant edema. The meningioma gradually shrank together with a decrease of edema and increase of calcification. The initial volume, 25.5 cm(3), regressed linearly to less than half, 9.9 cm(3).

CONCLUSION

Here, we report a case of an incidentally diagnosed meningioma that regressed spontaneously. The pattern of the regression was similar to that following gamma knife radiosurgery.

Spontaneous regression of renal cell carcinoma

Renal cell carcinoma (RCC) comprises 3-4% of all malignant tumours among adults in Poland. Spontaneous regression of RCC is a rare but well-known phenomenon. Its frequency is estimated to be approximately 1% and a large part of the percentage is accounted for by the regression of pulmonary metastases in the course of clear type of RCC treatment. We searched PubMed, Embase and SciVerse Scopus databases, identifying 59 case reports of spontaneous regression of RCC. Those medical histories come from reports from around the world and date back up to 40 years. This review includes their analysis as well as description of possible explanations of this phenomenon postulated by different authors, including both misdiagnosis and immunological reactions. This study indicates that reliable diagnostics and reporting of all the cases of spontaneous regression play a key role, as this is the only method which enables a better perspective in understanding this issue.