Breast Cancer: Early Symptoms Every Woman Should Know

1. Introduction

Breast cancer is the most commonly diagnosed malignancy in women worldwide and a leading cause of cancer-related mortality. According to the World Health Organization (WHO), approximately 2.3 million new breast cancer cases were recorded globally in 2022, accounting for nearly 12.5% of all new cancer diagnoses across both sexes. In India, breast cancer has now surpassed cervical cancer as the most prevalent female malignancy, contributing significantly to morbidity and healthcare burden in both urban and rural populations.

Despite major advances in oncology, late-stage diagnosis continues to undermine treatment outcomes. Studies consistently demonstrate that five-year survival rates for Stage I breast cancer exceed 99%, whereas Stage IV disease carries a survival rate of approximately 29% (American Cancer Society, 2023). This stark contrast underscores the critical importance of early detection through heightened symptom awareness, routine screening, and timely clinical evaluation.

This article, published in the New Bengal Journal of Medicine (NBJM), provides a comprehensive, evidence-based overview of breast cancer — from its epidemiology and pathophysiology to early clinical warning signs, diagnostic modalities, treatment strategies, and the latest research frontiers. It is intended to serve medical students, practising clinicians, and health-literate general readers alike.

 

2. Epidemiology and Background

The global incidence of breast cancer has risen steadily over recent decades, driven by shifting reproductive patterns, urbanisation, dietary changes, and improved reporting infrastructure. The International Agency for Research on Cancer (IARC) estimates that 1 in 12 women will develop breast cancer during their lifetime globally (IARC, 2022).

Global Burden

•        2.3 million new cases diagnosed worldwide in 2022 (WHO, 2023)

•        685,000 deaths attributed to breast cancer globally in 2020

•        Highest incidence rates: North America, Northern Europe, and Australia

•        Rapidly increasing incidence in South and East Asia, including India

Indian Context

•        India reports approximately 178,000 new breast cancer cases annually (ICMR, 2022)

•        Average age at diagnosis in India: 52 years — nearly a decade younger than Western counterparts

•        Over 60% of Indian cases are diagnosed at Stage III or IV due to limited awareness and access to screening

•        West Bengal and metropolitan cities like Kolkata reflect urban incidence trends, with increasing rates among younger women

The disparity in outcomes between high-income and low-to-middle-income countries (LMICs) remains a pressing public health concern. Targeted awareness campaigns, accessible mammographic screening, and empowered self-examination practices are essential tools for reversing late-diagnosis trends in India and similar settings.

 

3. Causes and Risk Factors

Breast cancer is a multifactorial disease arising from the interaction of genetic predisposition, hormonal influences, environmental exposures, and lifestyle factors. Understanding these risk determinants is essential for risk stratification and targeted preventive strategies.

Non-Modifiable Risk Factors

•        Female sex: Over 99% of breast cancers occur in women; male breast cancer constitutes less than 1% of cases

•        Age: Risk increases progressively with age; most cases are diagnosed in women over 50

•        Genetic mutations: BRCA1 and BRCA2 mutations confer a lifetime risk of 50–85% and 40–60% respectively (NEJM, 2021)

•        Family history: First-degree relative with breast cancer doubles individual risk

•        Personal history: Previous breast cancer or atypical ductal hyperplasia significantly elevates risk

•        Dense breast tissue: Mammographically dense breasts obscure tumours and independently increase risk

•        Early menarche (before age 12) and late menopause (after age 55): Prolonged oestrogen exposure

Modifiable Risk Factors

•        Hormone replacement therapy (HRT): Combined oestrogen-progesterone HRT increases risk by 26% (WHI, 2002)

•        Oral contraceptive use: Modest increase in relative risk during use; resolves after cessation

•        Nulliparity or first childbirth after age 30

•        Alcohol consumption: Each additional 10g of alcohol per day increases risk by approximately 7% (Lancet, 2019)

•        Obesity post-menopause: Adipose tissue produces oestrogens; BMI >30 increases risk by 20–40%

•        Physical inactivity: Sedentary lifestyle associated with 10–25% increased risk

•        Tobacco exposure: Emerging evidence links active and passive smoking to elevated risk

•        Radiation exposure: Particularly during adolescence; notably relevant for survivors of prior chest radiation

 

4. Pathophysiology

Breast cancer originates from the epithelial cells lining the ducts (ductal carcinoma) or lobules (lobular carcinoma) of the breast. The transformation from normal epithelium to invasive malignancy follows a stepwise process involving progressive accumulation of genetic and epigenetic alterations.

Molecular Mechanisms

The carcinogenic process is initiated by mutations in critical regulatory genes. Tumour suppressor genes — including TP53, BRCA1, BRCA2, PTEN, and CDH1 — normally maintain genomic stability and regulate apoptosis. When these are inactivated through somatic mutation, loss of heterozygosity, or epigenetic silencing, unchecked cellular proliferation ensues.

Concurrently, proto-oncogenes such as HER2 (ERBB2), MYC, and CCND1 may undergo amplification or activating mutations, providing a sustained proliferative signal. The HER2 receptor, overexpressed in approximately 20% of breast cancers, activates downstream PI3K/AKT and MAPK/ERK pathways, driving rapid tumour growth and conferring resistance to apoptosis.

Hormonal Pathways

Oestrogen plays a central role in the pathogenesis of hormone receptor-positive (HR+) breast cancers, which constitute approximately 70% of all cases. Oestrogen binds to oestrogen receptors (ER-alpha), translocates to the nucleus, and promotes transcription of growth-promoting genes including cyclin D1 and c-Myc. Progesterone receptors (PR) further modulate this response.

Tumour Classification

Modern molecular subtyping has identified four major intrinsic subtypes with distinct biological behaviour and therapeutic implications:

•        Luminal A (ER+/PR+, HER2-, low Ki-67): Favourable prognosis; responds well to endocrine therapy

•        Luminal B (ER+/PR+, HER2- or +, high Ki-67): Intermediate prognosis; may require chemotherapy

•        HER2-enriched (ER-, PR-, HER2+): Aggressive; responds to HER2-targeted therapy

•        Triple-negative (ER-, PR-, HER2-): Most aggressive subtype; lacks targeted therapy options; chemotherapy is standard

Invasion and Metastasis

As the tumour progresses, epithelial-mesenchymal transition (EMT) enables cancer cells to invade the basement membrane and surrounding stroma. Lymphovascular invasion facilitates spread to regional axillary lymph nodes — the most significant prognostic determinant in early-stage disease. Haematogenous spread results in distant metastases, most commonly to bone, lungs, liver, and brain.

 

 

 

5. Symptoms and Clinical Features

Early breast cancer is frequently asymptomatic, which is why screening programmes and breast self-examination (BSE) are indispensable. Nevertheless, a range of clinical signs may herald the presence of malignancy and must be taken seriously by both patients and clinicians.

Primary Warning Signs

•        A new, painless lump or thickening in the breast or axilla: The most common presenting symptom; not all lumps are malignant, but all require evaluation

•        Changes in breast size or shape: Asymmetry or unexplained change in contour warrants investigation

•        Skin changes: Dimpling, puckering, or tethering of the overlying skin — often indicating underlying fibrosis or tumour infiltration

•        Nipple changes: Inversion or retraction of a previously normal nipple; scaling or erosion (as seen in Paget's disease of the nipple)

•        Nipple discharge: Spontaneous, unilateral, bloodstained, or serous discharge from a single duct is particularly significant

•        Peau d'orange appearance: Skin resembling orange peel due to dermal lymphatic obstruction, characteristic of inflammatory breast cancer

•        Breast pain (mastalgia): Though most breast pain is benign, focal or persistent pain warrants investigation

•        Axillary or supraclavicular lymphadenopathy: Firm, non-tender nodes may indicate nodal spread

Signs Specific to Advanced Disease

•        Arm oedema (lymphoedema) due to axillary nodal involvement

•        Chest wall fixity of the mass

•        Ulceration of overlying skin in neglected cases

•        Systemic features: Weight loss, bone pain, breathlessness, or persistent headache may indicate metastatic disease

Inflammatory Breast Cancer (IBC)

Inflammatory breast cancer is a rare but aggressive clinical entity that may mimic mastitis. It characteristically presents without a discrete lump, manifesting instead as a rapidly enlarging, warm, erythematous, and oedematous breast. The absence of a palpable mass often leads to delayed diagnosis. IBC carries a poorer prognosis and requires prompt, aggressive management.

6. Diagnosis

The diagnostic workup for suspected breast cancer follows a systematic 'triple assessment' approach — combining clinical examination, imaging, and tissue sampling — to achieve maximum sensitivity and specificity.

Clinical Examination

A thorough clinical breast examination (CBE) by a trained healthcare professional remains fundamental. This involves bimanual palpation in both upright and supine positions, assessment of skin and nipple changes, and axillary lymph node palpation.

Imaging Modalities

•        Mammography: The gold-standard screening tool in women aged 40–74; sensitivity of 77–95% depending on breast density (USPSTF, 2024). Digital breast tomosynthesis (3D mammography) improves detection in dense breasts

•        Ultrasonography (USG): Preferred initial modality in women under 40 and for evaluating palpable lumps; distinguishes solid from cystic lesions; essential for image-guided biopsy

•        Magnetic Resonance Imaging (MRI): Reserved for high-risk screening (BRCA carriers), pre-surgical extent evaluation, and occult primary breast cancer; highest sensitivity but lower specificity

•        Positron Emission Tomography (PET-CT): Utilised for staging in locally advanced or metastatic disease

Tissue Diagnosis

•        Fine Needle Aspiration Cytology (FNAC): Rapid, minimally invasive; useful for palpable masses and axillary nodes

•        Core Needle Biopsy (CNB): Preferred method; provides histological architecture and receptor status

•        Excision biopsy: Reserved for non-diagnostic CNB or when complete removal is indicated

Histopathological and Molecular Assessment

All breast cancer tissue should undergo standardised assessment for ER, PR, HER2 status (via immunohistochemistry and FISH/CISH), and Ki-67 proliferative index. This guides molecular subtyping, predicts response to therapy, and informs prognosis. Genetic testing (BRCA1/2, PALB2) is recommended for patients meeting clinical criteria.

Staging

The AJCC TNM staging system (8th edition) integrates tumour size (T), nodal status (N), and metastatic spread (M) with biologic factors including tumour grade and receptor profile. Staging determines treatment intent and sequencing.

7. Treatment and Management

Breast cancer management has become highly personalised, integrating tumour biology, stage, patient fitness, and individual preferences. A multidisciplinary team (MDT) — encompassing surgical oncology, medical oncology, radiation oncology, radiology, pathology, and supportive care — is central to optimal decision-making.

Surgery

•        Breast-conserving surgery (BCS / lumpectomy): Excision of tumour with clear margins followed by adjuvant radiotherapy; oncologically equivalent to mastectomy in eligible patients (NEJM, 2002)

•        Modified radical mastectomy (MRM): Removal of the entire breast and axillary lymph nodes; indicated for larger tumours or patient preference

•        Sentinel lymph node biopsy (SLNB): Minimally invasive technique to assess nodal status, avoiding full axillary dissection and its associated morbidity

•        Oncoplastic surgery: Integration of plastic surgical techniques to optimise cosmetic outcomes

Systemic Therapies

•        Chemotherapy: Anthracycline- and taxane-based regimens remain the backbone for HER2+ and triple-negative disease; neoadjuvant chemotherapy facilitates BCS and provides pathological response data

•        Endocrine (Hormonal) Therapy: Tamoxifen (pre-menopausal) and aromatase inhibitors (post-menopausal) for HR+ disease; CDK4/6 inhibitors (palbociclib, ribociclib) in combination for advanced disease

•        HER2-targeted therapy: Trastuzumab (Herceptin), pertuzumab, and T-DM1 have transformed outcomes in HER2+ disease

•        Immunotherapy: Pembrolizumab is approved for high-risk early and metastatic triple-negative breast cancer (KEYNOTE-522 trial, 2022)

•        PARP inhibitors: Olaparib and talazoparib for BRCA1/2-mutated HER2-negative metastatic disease

Radiation Therapy

Adjuvant radiotherapy is standard following BCS and is utilised post-mastectomy in high-risk cases. Hypofractionation regimens (fewer, larger fractions) offer equivalent efficacy with improved convenience and reduced toxicity.

Supportive and Palliative Care

Psychosocial support, nutritional counselling, physiotherapy (for lymphoedema and post-surgical rehabilitation), and fertility preservation counselling are integral to holistic cancer care. In metastatic disease, palliation of symptoms and maintaining quality of life are paramount goals.

 

8. Prevention and Lifestyle Advice

While not all breast cancers are preventable, evidence supports that a significant proportion — estimated at 30–50% — may be avoidable through lifestyle modification and chemoprevention in high-risk individuals.

Primary Prevention

•        Maintain a healthy body weight: Target BMI 18.5–24.9; even modest weight loss in obese post-menopausal women reduces oestrogen levels

•        Regular physical activity: At least 150 minutes of moderate-intensity exercise per week (WHO Physical Activity Guidelines, 2020)

•        Limit alcohol intake: No safe threshold; minimising alcohol consumption is advisable

•        Avoid tobacco: Both active and passive smoking should be avoided

•        Breastfeeding: Each 12 months of cumulative breastfeeding reduces breast cancer risk by 4.3% (Lancet, 2002)

•        Minimise unnecessary hormone therapy: Discuss risks and benefits of HRT with an experienced clinician

Chemoprevention

Women at high risk (Tyrer-Cuzick score ≥30% lifetime risk) may benefit from chemoprevention with tamoxifen or raloxifene, which reduce ER+ breast cancer incidence by approximately 38% in high-risk cohorts (NSABP P-1 trial). Aromatase inhibitors are also approved in post-menopausal high-risk women.

Screening Guidelines

•        Clinical breast examination (CBE): Annually from age 40; or earlier for high-risk women

•        Mammography: Annually or biennially from age 40–50 depending on risk profile; most guidelines recommend annual screening from age 45 with shared decision-making

•        Breast self-examination (BSE): Monthly self-examination from age 20 to establish personal 'baseline'; any new change should prompt medical consultation

•        MRI screening: Annually from age 25–30 in BRCA carriers and other very high-risk individuals

Genetic Counselling

Women with a significant family history — particularly bilateral, premenopausal, or multi-generational breast cancer — should be referred for formal genetic risk assessment and counselling regarding BRCA testing. Risk-reducing bilateral salpingo-oophorectomy and risk-reducing mastectomy are evidence-based options for BRCA mutation carriers.

 

9. Recent Medical Research

The landscape of breast cancer research is rapidly evolving, with several practice-changing advances emerging in recent years.

Antibody-Drug Conjugates (ADCs)

Trastuzumab deruxtecan (T-DXd) has demonstrated remarkable efficacy in HER2-low breast cancer — a previously under-served molecular subtype comprising approximately 60% of all breast cancers. The DESTINY-Breast04 trial (NEJM, 2022) reported a median progression-free survival of 9.9 months versus 5.1 months with chemotherapy, fundamentally redefining treatment eligibility in this group.

Immunotherapy in TNBC

The KEYNOTE-522 trial established pembrolizumab plus chemotherapy as a new standard of care for high-risk early triple-negative breast cancer, with an 18% relative reduction in events at 5 years versus chemotherapy alone (NEJM, 2022). This represents the first immunotherapy approval in the early breast cancer setting.

Polygenic Risk Scores (PRS)

Genome-wide association studies (GWAS) have identified over 200 common genetic variants associated with breast cancer susceptibility. Polygenic risk scores incorporating these variants are being integrated into risk stratification models, with potential to personalise screening intervals and chemoprevention recommendations (Nature Genetics, 2023).

Liquid Biopsy

Circulating tumour DNA (ctDNA) detected in peripheral blood offers non-invasive real-time monitoring of tumour dynamics, treatment response, and early detection of resistance. ctDNA assays are advancing toward clinical utility for surveillance and minimal residual disease assessment.

Artificial Intelligence in Screening

Multiple large-scale studies have demonstrated that AI-assisted mammography reading achieves diagnostic accuracy equivalent to, or exceeding, double radiologist reading (Lancet Oncology, 2024). AI models offer the potential to reduce radiologist workload, increase access in resource-limited settings, and standardise screening quality globally.

Extended Endocrine Therapy

Long-term follow-up data from the ATLAS and aTTom trials confirm that extending adjuvant tamoxifen to 10 years further reduces late recurrence and breast cancer mortality in ER+ premenopausal patients, particularly beyond years 10–14, supporting re-evaluation of therapy duration in high-risk cases.

 

10. Conclusion

Breast cancer remains one of the most significant public health challenges facing women in India and worldwide. Yet it is also among the most tractable malignancies when detected early. The five-year survival advantage conferred by Stage I diagnosis compared to Stage IV disease is unequivocal, placing the imperative firmly on early detection, informed awareness, and access to timely, quality care.

For healthcare professionals, this demands vigilance during clinical assessment, systematic integration of the triple assessment model, and ongoing engagement with a rapidly evolving evidence base. For medical students, mastery of breast anatomy, the clinical spectrum of early and advanced disease, and the molecular basis of oncological therapy is foundational to modern clinical practice.

For the general public — and particularly for women — awareness of personal risk, familiarity with early warning signs, adherence to screening recommendations, and prompt presentation for any breast change are transformative, potentially life-saving behaviours. The New Bengal Journal of Medicine remains committed to bridging the knowledge gap between cutting-edge research and community-level understanding, in the service of better health outcomes for all.

 

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