HE-4 in the Diagnosis of Carcinoma of Ovary Presented as Unknown primary Carcinoma: A Case Report

Abstract

Ovarian cancer is the second most common gynecologic malignancy in the United States, with high mortality due to delayed diagnosis. Serum CA-125 is widely used for screening and monitoring but lacks sensitivity and specificity in some cases. We present a 67-year-old female diagnosed with advanced-stage ovarian cancer despite normal CA-125 levels, with elevated HE4 (human epididymis protein 4), underscoring its diagnostic value. This case highlights the importance of integrating HE4 with CA-125 in ovarian cancer evaluation and emphasizes a multimodal approach to enhance early detection and outcomes.

Introduction

Ovarian cancer often presents without early warning signs, leading to a diagnosis at advanced stages associated with poor prognosis. The clinical presentation in the early stages is typically nonspecific, and there are currently no standardized histologic screening methods for ovarian cancer. According to the American Cancer Society, approximately 19 680 new cases of ovarian cancer are expected in 2024, with about 12 740 deaths, making it one of the leading causes of cancer-related mortality among women. The identification of novel biomarkers for early detection could significantly reduce morbidity and mortality associated with the disease. CA-125 is one of the most widely used serum biomarkers for the evaluation of ovarian cancer. Additionally, human epididymis protein 4 (HE4) has also shown a strong association with the disease. However, clinical practice has demonstrated an underutilization of HE4 in the diagnostic process.

Our case reported an ovarian cancer in which CA-125 levels were within the normal range, while HE4 was markedly elevated. This case underscores the importance of incorporating HE4 testing at the diagnosis of metastasis of carcinoma of unknown primary with normal CA125 levels.

Case Presentation

We present a 67-year-old female with a past medical history of type 2 diabetes, obstructive sleep apnea on continuous positive airway pressure, hypertension, Gastroesophageal reflux disease (GERD), and hyperlipidemia. Her surgical history includes an ectopic pregnancy and hysterectomy for fibroid uterus years ago. The patient first presented to her primary care physician with worsening abdominal pain over several months but denied any significant weight loss. Physical examination revealed marked tenderness in the lower abdomen below the umbilicus, with mild tenderness noted in the right upper quadrant and epigastrium with abdominal fullness in the lower abdomen, otherwise was unremarkable. A CT scan identified a 6 cm irregular soft tissue mass associated with the pelvic wall muscles subjacent to a region of scarring which is bigger, compared with the previous CT, as well as a stable 4 cm complex left adnexal cyst (Figure 1). However, tumor markers including CA-125 and CEA, were within normal limits. Extraovarian peritoneal serous papillary carcinoma (EPSPC) was suspected, a rare malignant tumor that presents as peritoneal carcinomatosis without a clear primary site of origin. Historically, it was referred to as “mesothelioma of the pelvic peritoneum.” ¹ According to Patil et al, a diagnosis of EPSPC requires radiological evidence of a grossly normal uterus and adnexa. However, in this case, the criterion was not fully met, as CT imaging revealed a cystic lesion in the left hemipelvis, suggestive of an ovarian cyst. ²

Figure 1.

CT scan of abdomen and pelvis identified a 6 cm irregular soft tissue mass associated with the pelvic wall muscles subjacent to a region of scarring. Ovaries appear unremarkable.

She then underwent laparoscopic laparotomy and resection of the pelvic mass. Pathological analysis revealed metastatic adenocarcinoma with mucin production and positive perineural invasion (Figure 2). Immunohistochemical analysis showed positivity for CK7, PAX-8, estrogen receptor (ER), and MUC2, while markers WT-1, CK20, CDX2, and CEA were negative (Figure 2). ³ Next generation sequence studies failed to reveal BRCA1, BRCA2, or other homologous recommendation repair gene mutation. The combination of histomorphology and immunostaining findings confirmed a diagnosis of metastatic adenocarcinoma of Müllerian origin involving the abdominal wall. Additionally, the patient exhibited a significantly elevated HE4 level of 462 pmol/L (normal upper limit: 141 pmol/L). A subsequent PET/CT scan for staging revealed pulmonary metastases, including a 1 cm nodule in the periphery of the right upper lobe and mildly hypermetabolic soft tissue changes in the anterior pelvic wall. The biopsy showed consistent with gynecologic tract origin. The patient then underwent 6 cycles of treatment with Bevacizumab-bvzr, Paclitaxel, and Carboplatin. Following the completion of 5 out of 6 treatment cycles, the patient demonstrated a favorable recovery. A recent CT scan revealed a reduction in the pulmonary nodule size from 1 cm to 6 mm, with no signs of infiltration or any detectable adnexal tumor mass. However, the patient’s HE4 level remains elevated at 314 pmol/L, warranting continued follow-up to monitor for potential recurrence.

Figure 2.

Metastatic adenocarcinoma with Müllerian primary in the abdominal wall: The infiltrative clusters of neoplastic cells with cribriform formation with desmoplastic response are present in the abdominal wall. (A) The neoplastic cells are immunoreactive to PAX8. (B) MUC2. (C) CK7. (D) ER. (E) A small subset of the neoplastic cells are immunoreactive to CA125. (F) No immunoreaction to WT1, CDX2, CK20, CEA is highlighted in the neoplastic cells. ER, estrogen receptor.

Discussion

Ovarian cancer is the second most common gynecologic cancer in the United States and has the highest mortality rate among female reproductive cancers. The 5-year survival rate for advanced ovarian cancer is approximately 30.7% (Centers for Disease Control and Prevention, 2014-2020). Due to its atypical presentation, over 80% of ovarian cancer cases are diagnosed at an advanced stage. ⁴ Primary peritoneal cancer (PPC) is closely related to ovarian cancer, sharing embryological origins, pathological features, and clinical behavior. ⁵ PPC, known as a “silent killer,” has a worse prognosis than ovarian cancer and remains poorly understood.^6,7 An Australian study identified unique risk factors for PPC, such as parity, obesity, and BRCA mutations, even after prophylactic oophorectomy.^8-10 Advanced maternal age at last pregnancy was linked to increased PPC risk but reduced invasive serous epithelial ovarian cancer (EOC) risk. ¹¹ Other distinguishing factors include tubal ligation and a family history of breast cancer.

CA-125 is a widely used biomarker for ovarian cancer, elevated in about 80% of advanced EOC cases but only 50% of stage I cases.^12,13 Notably, 20% of advanced ovarian cancer patients have normal CA-125 levels. Combining CA-125 with HE4 enhances diagnostic accuracy in such cases. HE4 is encoded by the WFDC2 gene and is highly specific for ovarian cancer that does not get elevated in endometriosis or benign gynecological conditions.^14,15 Elevated CA-125 with normal HE4 often indicates endometriosis, whereas elevated HE4 without CA-125 may suggest ovarian or other malignancies. ¹⁶ Studies confirm HE4’s superior specificity in differentiating malignant from benign ovarian conditions.^17,18 Yanaranop et al reported HE4’s 86% specificity with an Area under the curve (AUC) of 0.893, outperforming CA-125 (AUC 0.865). ¹⁹ HE4 is particularly effective in detecting EOC, even in early stages.^20-22 A multi-center study by Romagnolo et al further supports HE4’s higher specificity in EOC diagnosis, particularly in early-stage cancers. ²⁰

In addition, despite aggressive combined treatment, around 75% to 85% of ovarian cancer patients relapse after first-line therapy and the recurrence rates vary by stage: around 10% in International Federation of Gynecology and Obstetrics (FIGO) stage I, 30% in stage II, and a sharp increase to 85% in stages III and IV. ²³ The high recurrence rate also emphasize the urgent need for more specific and sensitive markers. Yang et al measured HE4, anti-HE4 autoantibodies (AAb), and HE4 antigen-autoantibody (Ag-AAb) complexes in the sera of 73 early stage and 49 late stage ovarian cancer patients. At 98% specificity, elevated HE4 AAb levels were found in 7% of early-stage and 4% of late-stage cases, while HE4 Ag-AAb complexes were detected in 38% and 31%, respectively. Complementarity was observed between HE4 Ag-AAb complexes and CA125, which improved early-stage detection from 63% (CA125 alone) to 81% (combined, P < .001). ²¹ Notably, when used in combination with CA 125, it can improve both sensitivity and specificity for detecting and distinguishing ovarian cancer, which was recently approved by the FDA.^21,24 This led to the development of the risk of ovarian malignancy algorithm (ROMA), which combines HE4 and CA 125 levels, according to menopausal status and the effectiveness of ROMA has been validated in various populations by many studies.^24,25 So in early and late stage of carcinoma of ovary, HE-4 appeared to be more sensitive than CA125 in the diagnosis of ovarian cancer and combined use of these 2 marker may yielded more sensitivity and specificity.

HE4 also plays a significant role in predicting treatment response and prognosis. Allard et al demonstrated that HE4 levels correlate with clinical response and remission which assessed by CT imaging. ²⁶ Kotowicz et al reported HE4 as a stronger predictor of poor prognosis in advanced ovarian cancer, with elevated HE4 levels linked to disease progression post-treatment. ²⁷ Other studies also support this perspective, showing that HE4 serum levels are associated with disease progression. ¹⁵ Failure to normalize HE4 levels after therapy may indicate persistent disease, even when CA125 remains normal.^14,28 Some studies also suggests that HE4 is useful in detecting recurrence earlier than CA125.^26,28,29 Therefore HE-4 also appears to be an excellent marker for treatment response and prognosis in Ca of ovary.

PPC shares diagnostic and prognostic features with ovarian cancer, particularly with HE4 and CA125. While HE4 has lower sensitivity than CA125 in advanced PPC, it offers higher specificity and better differentiation from benign conditions. Mi et al reported that combining HE4 and CA125 improved early-stage PPC detection to 72.4% sensitivity. ³⁰ HE4 also demonstrated superior performance in monitoring treatment response, with a 76% effective response rate compared to 58% for CA125. ³¹ HE4 was identified as an independent prognostic factor for recurrence-free and overall survival, with hazard ratios of 5.36 and 4.48, respectively. ³² These findings highlight that the combined use of HE4 and CA125 significantly enhances sensitivity and specificity across diagnosis, prognosis, and recurrence assessments, particularly in advanced-stage PPC cases.^30-32

Our case demonstrated a presentation of late-stage ovarian cancer in which HE4 levels were elevated while CA125 remained normal. This pattern has been reported in previous studies. Manolov et al found that 30 of 55 ovarian cancer patients had elevated HE4 levels despite low CA125 levels. ³³ Similarly, Schummer et al highlighted HE4’s importance in cases with normal CA125. Among 23 patients with advanced ovarian or fallopian tube cancer, HE4 was the sole marker to rise before recurrence in 5 cases—1 patient never showed a CA125 response, and in 2 cases, HE4 rose earlier than CA125. Notably, in 4 of 7 cases, HE4 remained elevated during remission even when CA125 and imaging results were negative. ³⁴ These findings draw attention to the value of HE4 as a tumor marker for screening and monitoring ovarian cancer in both early and late stages. In a study by Nolen et al multiplex assays evaluated 65 biomarkers for their ability to differentiate between malignant and benign pelvic masses, with CA125 and HE4 showing the highest level of discrimination. ³⁵ Combining CA125 and HE4, as seen in the ROMA algorithm, may play a pivotal role in future ovarian cancer diagnostics. Bast et al reported ROMA achieved 94% sensitivity at 75% specificity (P = .0029). And ROMA can detected 85% of patients particularly in stage I and II ovarian cancers. ³⁶ While biomarkers alone cannot confirm a diagnosis, as the gold standard remains biopsy, combining HE4 and CA125, as in the ROMA, provides higher sensitivity and specificity. This combination significant enhances early detection of malignant ovarian cancer and peritoneal cancer and facilitating timely intervention.

Conclusion

HE4 shows comparable diagnostic performance to CA 125 in detecting ovarian cancer and peritoneal cancer, with higher sensitivity for early-stage disease and greater specificity. Combining HE4 with CA 125 enhances the accuracy of detecting ovarian cancer, improving differentiation between benign and malignant ovarian lesions. HE4 is also a more reliable marker for assessing treatment response, predicting prognosis, and early recurrence detection, especially in patients with low CA 125 levels. Additionally, persistent elevated HE4 levels following standard therapy may indicate a poor prognosis.