The Challenge
Cancer risk prediction is one of the most impactful applications of machine learning in healthcare. Early detection saves lives — but building a reliable prediction system requires more than just training a single model.
Why Ensemble Learning?
No single ML algorithm performs best across all cancer types and patient demographics. Our approach: combine multiple models and let them vote.
class CancerEnsemblePredictor:
def __init__(self):
self.models = {
'xgboost': XGBClassifier(
n_estimators=500,
max_depth=6,
learning_rate=0.01,
subsample=0.8,
colsample_bytree=0.8
),
'lightgbm': LGBMClassifier(
n_estimators=500,
num_leaves=31,
learning_rate=0.01,
feature_fraction=0.8
),
'random_forest': RandomForestClassifier(
n_estimators=300,
max_depth=10,
min_samples_split=5
),
'neural_net': self._build_neural_network()
}
self.meta_learner = LogisticRegression()
def _build_neural_network(self):
model = Sequential([
Dense(256, activation='relu', input_shape=(feature_count,)),
BatchNormalization(),
Dropout(0.3),
Dense(128, activation='relu'),
BatchNormalization(),
Dropout(0.2),
Dense(64, activation='relu'),
Dense(1, activation='sigmoid')
])
model.compile(optimizer='adam', loss='binary_crossentropy')
return modelThe Stacking Architecture
We use a two-level stacking approach:
This consistently outperforms any individual model by 3-7% on our validation set.
Data Pipeline
Patient data flows through a rigorous preprocessing pipeline:
API Architecture
The backend exposes 69 REST endpoints organized by role:
Blood Donor Geo-Matching
A unique feature is our blood donor geo-matching system. When a patient needs a transfusion:
async def find_nearest_donors(
patient_location: GeoPoint,
blood_type: str,
radius_km: float = 25.0,
limit: int = 10
) -> list[DonorMatch]:
compatible_types = get_compatible_blood_types(blood_type)
donors = await db.donors.find({
'blood_type': {'$in': compatible_types},
'is_available': True,
'last_donation_date': {'$lt': thirty_days_ago},
'location': {
'$nearSphere': {
'$geometry': patient_location,
'$maxDistance': radius_km * 1000
}
}
}).limit(limit)
return [DonorMatch(
donor=d,
distance=calculate_distance(patient_location, d.location),
compatibility_score=score_compatibility(blood_type, d.blood_type)
) for d in donors]Results
Privacy & Compliance
All patient data is encrypted at rest and in transit. We follow HIPAA guidelines for data handling, with role-based access control and complete audit logging.